Which claim does the author make through a discussion of jenner’s discoveries related to cowpox and smallpox?

jenner’s research distinguished cowpox from smallpox.
jenner’s research led to the creation of a smallpox vaccine.
jenner’s research was responsible for the elimination of many diseases.
jenner’s research was a result of a conversation he had with a dairymaid.

The correct option is "Jenner’s research led to the creation of a smallpox vaccine."

Edward Jenner is called "the father of immunology," and it is said that his work "has saved more lives than any other man's work." He became a well-known researcher, rural doctor and poet, whose discovery of the vaccines was very important to combat smallpox. In the field of zoology, he was the first person to describe the cuckoo's parasitism.