20. What should be done to these equations in order to solve a system of equations by elimination?

[tex][tex]\[
\left\{
\begin{array}{c}
-3x + 2y = 16 \\
2x + 5y = 21
\end{array}
\right.
\][/tex][/tex]

A. Multiply the first equation by 3.
B. Multiply the first equation by 3 and the second equation by 2.
C. Multiply the first equation by 2 and the second equation by 3.
D. Nothing needs to be done, since they both have 2's and 3's for coefficients.