1. It is known that f(n) = (2n+7) 3n+9, and there is a natural number m, so that for any n∈N, m can be divisible by f(n), then the maximum value of m is ()?

A.30 B.26 C.36 D.6？

2. Prove that 3k≥n3(n≥3, n∈N) by mathematical induction. The first step should be to verify ()?

A.n= 1 B.n=2？ C.n=3 D.n=4