[" 13.A man squatting on the ground gets straight up and "],[" The force of reaction of ground on the man durng,"],[" process is "],[" (a) Constant and equal to "mg" in magnitude "],[" (b) Constant and greater than mg in magnitude "],[" (c) Variable but always greater than "mg],[" (d) At first greater than "mg" and later becomes equaltoms "]