Dining and sleeping passenger railroad cars allowed people to make long trips in more comfortable conditions.
• automobiles could people travel long distances in a less time than wagons.
• electric streetcars could take people to many places around cities.

which of the following would be an appropriate title for the box above?
"examples of innovations in transportation changing 19th century americans' lives"
"reasons why transportation caused pollution and waste in the united states"
"how modern transportation systems connected cities from the atlantic to the pacific"
"modern transportation's negative impacts on american society in the 1800s"