In a triangle $ABC, \; a = 4, \; b = 3, \; \angle{A} = 60^{\circ}$, then $c$ is the root of the equation :

Question

( A ) $c^2 - 3c - 7 = 0$
( B ) $c^2 +3c+7=0$
( C ) $c^2 - 3c + 7 = 0$
( D ) $c^2 + 3c - 7 =0$