Multiply the Expression as You Would Multiply Polynomials $\left( a ^ { 19 / 2 } + b ^ { 9 / 2 } \right) \left( a ^ { 19 / 2 } - b ^ { 9 / 2 } \right)$

Multiple Choice

Multiply the expression as you would multiply polynomials. $\left( a ^ { 19 / 2 } + b ^ { 9 / 2 } \right) \left( a ^ { 19 / 2 } - b ^ { 9 / 2 } \right)$

A) $\quad ( a - b ) ^ { 14 }$
B) $\quad a ^ { 38 } - b ^ { 18 }$
C) $\quad (a - b ) ^ { 5 }$
D) $\quad a ^ { 19 } - b ^ { 9 }$