Write the Corresponding Rectangular Equation for the Curve Represented by the Parametric

Multiple Choice

Write the corresponding rectangular equation for the curve represented by the parametric equations $x = 9 \cos \theta , y = 9 \sin \theta$
by eliminating the parameter.

A) $x ^ { 2 } + y ^ { 2 } = 18$
B) $x + y = 9$
C) $x + y = 18$
D) $x ^ { 2 } + y ^ { 2 } = 9$
E) $x ^ { 2 } + y ^ { 2 } = 81$