Add or Subtract as Indicated $\left( 13 x ^ { 4 } + 2 x ^ { 2 } \right) - \left( - 5 x ^ { 4 } + 2 x ^ { 2 } \right)$

Multiple Choice

Add or subtract as indicated. Express the answer as a single polynomial in standard form.
- $\left( 13 x ^ { 4 } + 2 x ^ { 2 } \right) - \left( - 5 x ^ { 4 } + 2 x ^ { 2 } \right)$

A) $8 x ^ { 4 } + 4 x ^ { 2 }$
B) $18 x ^ { 4 } + 4 x ^ { 2 }$
C) $18 x ^ { 4 } + 0 x ^ { 2 }$
D) $18 x ^ { 6 }$