Find the Indicated Sum or Difference $$\left( - 3 z ^ { 2 } + 1 \right) + \left( 7 z ^ { 2 } - 1 \right)$$

Multiple Choice

Find the indicated sum or difference. $$\left( - 3 z ^ { 2 } + 1 \right) + \left( 7 z ^ { 2 } - 1 \right)$$

A) $4 z ^ { 2 } + 2$
B) $13 z ^ { 4 }$
C) $4 z ^ { 4 }$
D) $4 z ^ { 2 }$
E) $10 z ^ { 2 }$