Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
-The coefficient of $x ^ { 8 }$ in the expansion of $\left( x ^ { 2 } - 3 \right) ^ { 7 }$

A) 945
B) $- 945$
C) 2835
D) $- 2835$