first you need to find (h, k) by using the midpoint formula with the foci.
(0,-1) (0,-7)
(h, k) = (x1 + x2)/2 , (y1 + y2)/2
(h, k) = (0+0)/2 , (-1-7)/2
(h, k) = 0 , -4
so now you have
h = 0
k = -4
which means it can't be C or D
the vertices are 5 units away from the center, so
a = 5
this means that B has to be the answer
