Excerpt from The Appalachian Trail
Sasha Peterson

1The Appalachian Trail, which is officially called the Appalachian National Scenic Trail, is a path that stretches from Mount Katahdin in Maine, to Springer Mountain in Georgia. Measuring about 2,175 miles long, the trail is the longest marked footpath in the nation. The trail crosses fourteen states, eight national forests, and six national parks. The trail's lowest elevation is at Bear Mountain, New York, which is only 124 feet above sea level. The trail's highest elevation is at Clingman's Dome in Tennessee, which measures 6,625 feet above sea level.

2The trail is a part of the National Park Service. Over thirty trail clubs and many private partnerships help maintain the trail. Every year, more than 6,000 volunteers put in nearly 200,000 hours of work on the trail. More than 10,000 people have hiked the entire length of the trail, which takes five million footsteps to complete. The Appalachian Trail is one of the most beloved and well-known foot trails in the country.

3The Appalachian Trail began in 1921 as an idea suggested by Harvard University graduate and forester Benton MacKaye. MacKaye outlined his idea in a journal article titled "An Appalachian Trail: A Project in Regional Planning." The article first appeared in the Journal of the American Institute of Architects in 1921. In the article, MacKaye said that keeping the forest safe was an important part of protecting the country.

4In 1922, Major William A. Welch—director of the Palisades Interstate Park Commission—picked up on the idea and suggested that it be printed in the New York Evening Post. In 1925, a two-day Appalachian Trail Conference was held in Washington, DC. Many government officials supported the idea, and the first section of trail opened in 1928. The trail was completed in 1937. The Appalachian Trail was one of the first trails to be included in the National Trail System in 1968.

5Today, the Appalachian Trail Conference, which has become the Appalachian Trail Conservancy, helps protect the trail for future generations. The trail is home to more than 2,000 types of plants and animals. In fact, the trail has so many different life forms that experts believe it be the most naturally varied attraction in the National Park Service.

6The reason the trail contains such a wide variety of plants and animals is because the Appalachian Mountains stretch from Alabama to Canada. The many different climates and locations of the trail allow all different types of animals and plants to live there. Experts believe that the trail is not only important because of its natural variety, but also because of the many forests and waterways that it protects.
Which BEST summarizes this source?

A) The longest footpath in the United States, the popular Appalachian National Scenic Trail, crosses several states and is approximately 2,175 miles long. It is part of the National Park Service and maintained by many volunteer groups. This trail began as an idea in 1921 that drew interest and support. By 1928, the first section of the trail was open. The trail is home to over 2,000 types of plants and animals and protects forests and waterways.
B) The Appalachian Trail is officially called the Appalachian National Scenic Trail. It began in 1921 as an idea suggested by Harvard University graduate and forester Benton MacKaye. MacKaye outlined his idea in a journal article titled "An Appalachian Trail: A Project in Regional Planning." The article first appeared in the Journal of the American Institute of Architects in 1921. In the article, MacKaye said that keeping the forest safe was an important part of protecting the country.
C) The longest footpath in the United States, the popular Appalachian National Scenic Trail, crosses several states and is approximately 2,175 miles long. The trail contains a wide variety of plants and animals because the Appalachian Mountains stretch from Alabama to Canada. The many different climates and locations of the trail allow all different types of animals and plants to live there. This is not only important because of its natural variety, but also because of the many forests and waterways that it protects.
D) The Appalachian Trail is officially called the Appalachian National Scenic Trail. It is a path that stretches from Mount Katahdin in Maine, to Springer Mountain in Georgia. It measures about 2,175 miles long, making it the longest marked footpath in the country. The trail crosses fourteen states, eight national forests, and six national parks. The trail is a part of the National Park Service. Over thirty trail clubs and many private partnerships help maintain the trail. Every year, more than 6,000 volunteers put in nearly 200,000 hours of work on the trail.