Any ideas? I cant understand what its asking and although i'm trying my best i don't get it

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

5× 1/2 = ? a) more than 5 because you are multiplying by a whole number b) 5/10 because you multiply the numerator and denominator by 5 c) less than 5 because you are multiplying by a number that is more than 1 d) less than 5 because you are multiplying by a number that is less than 1

Can you me find the missing length. i attached an image.