Part of the following sentence is underlined; beneath the sentence are five ways of phrasing the underlined material. Select the option that produces the best sentence. If you think the original phrasing produces a better sentence than any of the alternatives, select choice A. 

The first public botanical garden in the United States, the Elgin Botanic Garden in New York City was established to provide plant materials for studying by medical students.

1.   for studying by medical students
2.   for medical students to study
3.   to medical students for their study
4.   for the study of medical students
5.   that medical students will study