In the United States in 2014, the highest marginal tax rate for individual income taxes was 39.6%

To determine the marginal physical product of labor, you must

a. hold total output constant and calculate how much revenue an additional worker generates b. hold capital constant and calculate how much revenue an additional worker generates hold capital constant c. hold all other factors of production constant and calculate how much output an additional worker produces d. hold labor constant and calculate how much output an additional worker produces e. hold labor constant and calculate how much revenue an additional worker generates

Starting a fishing business

a. is safe because the price of fish is stable b. requires little prior knowledge c. involves no significant entry costs d. is a risky way to make a living e. does not involve opportunity costs