Solution:Statement A. B, D and E are true pertaining to the marginal rate of substitution of two goods.
(A) MRS is the rate at which consumer substitutes one good for the other.
(B) MRS falls as we move down the indifference curve from left to right.
(D) If MRS along the IC remains constant, then the IC is a straight line.
(E) If MRS for two goods is zero or infinite, ICs are shaped as right angles.