The 550 Students Answered an Additional Question with the Following

The 550 students answered an additional question with the following results based on their rating of their instructor:
$$\begin{array} { | c | c | c | } \hline & \text { Very or Somewhat Effective } & \text { Very or Somewhat Ineffective } \\\hline \text { Final Grade } & & \\\hline \text { A } & 190 & 85 \\\hline \text { B } & 75 & 120 \\\hline \text { C } & 20 & 17 \\\hline \text { D } & 9 & 18 \\\hline \text { F } & 1 & 15 \\\hline\end{array}$$
-What proportion of the books purchased were self-help books?

A) 0.1144
B) 11.44
C) 1.82
D) 0.0182
E) 0.940