The Following Reaction Is Second Order in [A] and the Rate

The following reaction is second order in [A] and the rate constant is 0.025 M^-1s^-1: A → B
The concentration of A was 0.65 M at 33 s. The initial concentration of A was ________ M.

A) 2.4
B) 0.27
C) 0.24
D) 1.4
E) 1.2 × 10^-2