FERMAT 2021 Problem 21

A function, f, has f(2)=5 and f(3)=7. In addition, f has the property that

f(m)+f(n)=f(m n)

for all positive integers m and n. (For example, f(9)=f(3)+f(3)=14.) The value of f(12) is

Answer Choices
A. 17
B. 35
C. 28
D. 12
E. 25