4. A physics student looking into a carnival funhouse mirror sees that his image is upright but his head appears twice as big as normal and his feet look half as big as normal. Let o represent the distance from the student to the mirror, fo represent the focal length of the top of the mirror (where the student's head appears), and f represent the focal length of the bottom of the mirror (where the student's feet appear). What combination of curved mirrors is necessary to create the illusion? A) The mirror top is concave with f = 20 and the mirror bottom is convex with fo =-(1/2). B) The mirror top is concave with f = 20 and the mirror bottom is convex with =-0. The mirror top is concave with f = 30 and the mirror bottom is convex with f = - (1/3). D) The mirror top is convex with f = -s and the mirror bottom is concave with = (1/2)