Simplify the Expression $x ^ { ( 6 + 6 a ) } \cdot x^{ ( 8 a + 6 )}$

Multiple Choice

Simplify the expression. Assume that all variables represent nonzero integers.
- $x ^ { ( 6 + 6 a ) } \cdot x^{ ( 8 a + 6 ) }$

A) $x ^ { 2 a + 12}$
B) $x ^ { 2 a + 6}$
C) $x ^ { - 2 a }$
D) $x ^ { 14 a + 12 }$