Perform the Desired Operation $$( 5 + 2 i ) ( 5 - 2 i )$$

Multiple Choice

Perform the desired operation. Write the answer in the form a + bi.
- $$( 5 + 2 i ) ( 5 - 2 i )$$

A) $25 - 4 \mathrm { i } ^ { 2 }$
B) $25 - 4 \mathrm { i }$
C) 29
D) 21