For the Given Rectangular Equation, Give Its Equivalent Polar Equation $$x ^ { 2 } + y ^ { 2 } = 100$$

Multiple Choice

For the given rectangular equation, give its equivalent polar equation.
- $$x ^ { 2 } + y ^ { 2 } = 100$$

A) $r = 10$
B) $r = 10 \sin \theta$
C) $\mathrm { r } = 100$
D) $\mathrm { r } = 10 \cos \theta$