Find the Standard Form of the Equation of the Ellipse $= 12 ;$

Multiple Choice

Find the standard form of the equation of the ellipse satisfying the given conditions.
-Major axis horizontal with length 20 ; length of minor axis $= 12 ;$ center $( 0,0 )$

A) $\frac { x ^ { 2 } } { 100 } + \frac { y ^ { 2 } } { 36 } = 1$
B) $\frac { x ^ { 2 } } { 36 } + \frac { y ^ { 2 } } { 100 } = 1$
C) $\frac { x ^ { 2 } } { 20 } + \frac { y ^ { 2 } } { 36 } = 1$
D) $\frac { x ^ { 2 } } { 400 } + \frac { y ^ { 2 } } { 144 } = 1$