Solve the Differential Equation $4 y ^ { \prime \prime } + y = 0$

Multiple Choice

Solve the differential equation. $4 y ^ { \prime \prime } + y = 0$

A) $y ( x ) = c _ { 1 } \cos \left( - \frac { x } { 4 } \right) + c _ { 2 } \sin \left( - \frac { x } { 2 } \right)$
B) $y ( x ) = c _ { 1 } \cos ( 4 x ) - c _ { 2 } \sin ( 4 x )$
C) $y ( x ) = c _ { 1 } \cos ( 2 x ) + c _ { 2 } \sin ( 2 x )$
D) $y ( x ) = c _ { 1 } \cos ( - 2 x ) + c _ { 2 } \sin ( - 2 x )$
E) $y ( x ) = c _ { 1 } \cos \left( \frac { x } { 2 } \right) + c _ { 2 } \sin \left( \frac { x } { 2 } \right)$