Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?
x squared over 8 plus y squared over 4 equals 1
x squared over 16 plus y squared over 4 equals 1
x squared over 8 minus y squared over 4 equals 1
x squared over 16 minus y squared over 4 equals 1