Nurses Can Apply for a Variety of Grants from NIH

Nurses can apply for a variety of grants from NIH. What is the most common type of grant?
1) Research Project Grants
2) AREA Grants
3) Small Grants
4) Exploratory/Developmental Grants

A) 1
B) 1, 2
C) 1, 2, 3
D) 1, 2, 3, 4