The General Solution Of $y ^ { \prime \prime } + n ^ { 2 } y = 0 , y ( 0 ) = 0 , y ( \pi ) = 0 , n = 1,2,3 \ldots$

Multiple Choice

The general solution of $y ^ { \prime \prime } + n ^ { 2 } y = 0 , y ( 0 ) = 0 , y ( \pi ) = 0 , n = 1,2,3 \ldots$ is

A) $y = 0$
B) $y = c \cdot \sin ( n x )$
C) $y = c \cdot \cos ( n x )$
D) $y = c \left( e ^ { n x } - e ^ { - n x } \right)$
E) $y = c \left( e ^ { n x } + e ^ { - n x } \right)$