2015 Fermat Problem 15

A music test included 50 multiple choice questions. Zoltan's score was calculated by

- adding 4 points for each correct answer, - subtracting 1 point for each incorrect answer, and - adding 0 points for each unanswered question.

Zoltan answered 45 of the 50 questions and his score was 135 points. The number of questions that Zoltan answered *incorrectly* is

\textbf{(A)}\ 9\quad \textbf{(B)}\ 15\quad \textbf{(C)}\ 41\quad \textbf{(D)}\ 40\quad \textbf{(E)}\ 5

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Fermat contests here.