dont know for that rule...

never heard of it.

Anyway the rules for anything in math are the same everywhere.

ellipse formula is:

( x/a )^2 + ( y/b )^2 = 1

and the right answer is B) because you have ( 4, -3 ) , ( 4, -9 ) // ( x, y )

if you put x = 4 in B) you will get y1 = -3, y2 = -9