Solve the Problem $f ( \theta ) = \cot \theta$ And $f ( a ) = - 4$

Multiple Choice

Solve the problem.
-If $f ( \theta ) = \cot \theta$ and $f ( a ) = - 4$ , find the exact value of $f ( a ) + f ( a + \pi ) + f ( a + 3 \pi )$ .

A) $- 4$
B) $- 12 + 4 \pi$
C) $- 12$
D) undefined