Which is the equation of an ellipse centered at the origin with foci on y-axis, x-intercepts +1 and y-intercepts +8?
a. x^2/2 + y^2/64=1
b. x^2/1 + y^2/64=1
c. x^2/64+y^2/1=1
d. x^2+y^2/8=1
