Perform the Indicated Operation $( 7 c + 3 d ) ( 7 c - 3 d )$

Multiple Choice

Perform the indicated operation: $( 7 c + 3 d ) ( 7 c - 3 d )$

A) $49 c ^ { 2 } - 9 d ^ { 2 }$
B) $14 c ^ { 2 } - 6 d ^ { 2 }$
C) $49 c ^ { 2 } - 2 c d - 9 d ^ { 2 }$
D) $49 c ^ { 2 } - 42 c d + 9 d ^ { 2 }$