Economists define economic profit as a return greater than the opportunity cost or price of the capital employed. economic profit is the return to bearing uncertainty. (accounting profit is the residual attributed to capital after all other costs have been paid). in a world of certainty which statement is true?

The controlled use of fire by hominids: (a) limited the expansion of hominids into certain environments, such as dry grasslands. (b) decreased the amount of food energy available in the hominid diet. (c) contributed to geographical expansion and food production techniques in positive ways. (d) has been shown to contribute little to the digestive process of hominids.