Graph the Ellipse and Locate the Foci $$9 x ^ { 2 } + 4 y ^ { 2 } = 36$$

Graph the ellipse and locate the foci.
- $$9 x ^ { 2 } + 4 y ^ { 2 } = 36$$

A) foci at $( 0 , \sqrt { 5 } )$ and $( 0 , - \sqrt { 5 } )$

B) foci at $( \sqrt { 5 } , 0 )$ and $( - \sqrt { 5 } , 0 )$

C) foci at $( \sqrt { 13 } , 0 )$ and $( - \sqrt { 13 } , 0 )$

D) foci at $( 2 \sqrt { 3 } , 0 )$ and $( - 2 \sqrt { 3 } , 0 )$