(A) : Myopia can be corrected by using concave lens.
(R) : Nearsightedness is due to too much of convergence of incident beam

In a myopic eye, the image of a distant object is formed in front of the retina and not at the retina itself. A concave(diverging) lens causes light rays to diverge before they strike the lens of the eye so that the image is formed on the retina. Hence, a concave lens is used to correct myopia.