What is the concentration of $A$ at time $45\;s$ if $[A]_o = 1\;M$, $[B]_o = 45\;M$, and 2nd order rate constant is $0.6\;M^{-1}s^{-1}$?

Question

$\begin{array}{1 1} 1.88 \times 10^{-12}\;M \\ 3.76 \times 10^{-12}\;M \\ 0.94 \times 10^{-12}\;M \\ 4.7 \times 10^{-12}\;M \end{array}$