The equation of the ellipse whose foci are `(+-2, 0)` and eccentricity is 1/2, is :
`(x^2)/12 + (y^2)/16 = 1`
`(x^2)/16 + (y^2)/12 = 1`
`(x^2)/16 + (y^2)/8 = 1`
none of these
how to solve it.