A) increases as pollution abatement increases because people learn to want an even cleaner environment as the environment gets cleaner.
B) decreases as pollution abatement increases because of the law of diminishing marginal product.
C) is constant as pollution abatement increases because pollution abatement is valued for its own sake and not for the utility it provides.
D) decreases as pollution abatement increases because of the law of diminishing marginal utility.