Perform the Multiplication and Use the Fundamental Identities to Simplify $( \sin x + \cos x ) ^ { 2 }$

Multiple Choice

Perform the multiplication and use the fundamental identities to simplify.
$( \sin x + \cos x ) ^ { 2 }$

A) $1 + \sin x + \cos x$
B) $1 + \sin x \cos x$
C) $1 + 2 \sin x + \cos x$
D) $1 + 2 \sin x \cos x$
E) $2 + 2 \sin x \cos x$