Factor the Following Trinomial Assuming That All Variables Appearing as Exponents

Multiple Choice

Factor the following trinomial assuming that all variables appearing as exponents represent positive integers. $x ^ { 2 a } + 10 x ^ { a } + 24$

A) $\left( x ^ { a } + 6 \right) \left( x ^ { a } + 4 \right)$
B) $\left( x ^ { a } - 6 \right) \left( x ^ { a } + 4 \right)$
C) $( x + 6 ) ( x + 4 )$
D) $\left( x ^ { a } + 6 \right) \left( x ^ { a } - 4 \right)$
E) $\left( x ^ { a } - 6 \right) \left( x ^ { a } - 4 \right)$