Find All Complex Zeros of the Polynomial Function $$f ( x ) = x ^ { 4 } - 21 x ^ { 2 } - 100$$

Multiple Choice

Find all complex zeros of the polynomial function. Give exact values. List multiple zeros as necessary.
- $$f ( x ) = x ^ { 4 } - 21 x ^ { 2 } - 100$$

A) $- 2 \mathrm { i } , 2 \mathrm { i } , 10 \mathrm { i } , - 10 \mathrm { i }$
B) $- 2 \mathrm { i } , 2 \mathrm { i } , 10 , - 10$
C) $- 2 i , 2 i , 5 i , - 5 i$
D) $- 2 \mathrm { i } , 2 \mathrm { i } , 5 , - 5$