For the Data in the Following Table, Which Level of Q

Multiple Choice

For the data in the following table, which level of q will maximize profit? $$\begin{array} { l l l } \hline \mathrm { q } & \mathrm { MR } & \mathrm { MC } \\\hline 0 & 0 & 0 \\10 & 40 & 10 \\20 & 30 & 20 \\30 & 20 & 30 \\40 & 10 & 40 \\50 & 5 & 50 \\\hline\end{array}$$

A) 10
B) 20
C) 30
D) 40