Factor Out the Greatest Common Factor $$14 x ^ { 3 a } - 4 x ^ { 2 a } + 10 x ^ { a }$$

Multiple Choice

Factor out the greatest common factor. Assume that variables used as exponents represent positive integers.
- $$14 x ^ { 3 a } - 4 x ^ { 2 a } + 10 x ^ { a }$$

A) $2 x ^ { a } \left( 7 x ^ { 2 a } - 2 x ^ { a } + 5 \right)$
B) $x ^ { a } \left( 14 x ^ { 2 a } - 4 x ^ { a } + 10 \right)$
C) $2 \left( 7 x ^ { 3 a } - 2 x ^ { 2 a } + 5 x ^ { a } \right)$
D) $2 x ^ { a } \left( 7 x ^ { 3 a } - 2 x ^ { 2 a } + 5 x ^ { a } \right)$