Identify the correct general solution to the second order differential equation which describes free vibration with no damping.

A. $x(t) = C\sin(\omega_nt + \phi)$
B. $x(t) = \omega_n\sin(Cx + t)$
C. $x(t) = C\sin(x + t) + D\cos(x + t)$
D. $x(t) = A\sin(\omega_dt + C) + B\cos(\omega_dt + D)$