A test consists of 25 problems and students are told to answer any 15 of these questions. In how many different ways can they choose the 15 questions?

A. 480,700

B.1,081,575

C.2,042,297

D.3,268,760

Find the 4th terms in (a + 4)8.

A.-3594a5

B.3594a5

C.-3584a5

D.3584a5