Choose the correct statements in the context of the law of diminishing marginal utility

(A) States that each successive unit of a commodity provides lower marginal utility.
(B) States that each successive unit of a commodity provides higher marginal utility.
(C) Explains why demand curves have a negative slope.
(D) States that the marginal utility from consuming each additional unit of a commodity declines as its consumption increases, while keeping consumption of other commodities constant.

Choose the correct answer from the options given below:

(A), (C) and (D) only

The correct answer is Option (4) → (A), (C) and (D) only

(A) States that each successive unit of a commodity provides lower marginal utility. (Correct). This is the basic definition of the law of diminishing marginal utility: as a consumer consumes more units of a good, the additional satisfaction (marginal utility) from each extra unit diminishes.
(B) States that each successive unit of a commodity provides higher marginal utility. (Incorrect). This is the opposite of the law of diminishing marginal utility. If marginal utility were to increase, consumers would want to consume an infinite amount of a good, which isn't realistic.
(C) Explains why demand curves have a negative slope. (Correct).The law of diminishing marginal utility is a key reason for the downward-sloping demand curve. As a consumer gets less additional satisfaction from each subsequent unit, they are only willing to buy more units if the price decreases.
(D) States that the marginal utility from consuming each additional unit of a commodity declines as its consumption increases, while keeping consumption of other commodities constant. (Correct).This is a more precise and complete definition of the law of diminishing marginal utility, including the ceteris paribus (all else equal) assumption often used in economics.