The correct answer is: C. Convex lens.
A convex lens is a lens that bulges outward at the center. It is thicker at the center than at the edges. Convex lenses are used in magnifying glasses, microscopes, and telescopes to make objects appear larger.
A plano-concave lens is a lens that is flat on one side and concave on the other. A concave lens is a lens that curves inward at the center. It is thinner at the center than at the edges. Concave lenses are used in eyeglasses to correct nearsightedness.
A cylindrical lens is a lens that is curved in one direction but flat in the other. Cylindrical lenses are used to correct astigmatism, a condition in which the cornea is not perfectly round.
A convex lens is the correct answer because it is the only type of lens that can make objects appear larger.