1. The marginal benefit from pollution abatement

-increases as pollution abatement increases because people learn to want an even cleaner environment as the environment gets cleaner.

-decreases as pollution abatement increases because of the law of diminishing marginal utility.

-is constant as pollution abatement increases because pollution abatement is valued for its own sake and not for the utility it provides.

-decreases as pollution abatement increases because of the law of diminishing marginal product.