請問可吾可以help我呀

In Economics, the cost of an event is the highest-valued opportunity necessarily forgone. An event may be a production, consumption or any decision. Cost of production concerns the value of resources used up in the process of production.

The usefulness of the concept of cost is a logical implication of choice among available options. Only if no alternatives were possible, or if resources were available in amounts exceeding everyone's desires, would the concepts of cost and choice be irrelevant.

If choices are made on anything, a criterion of choice is implied. Whatever the criterion, the chosen option will involve a loss of the highest-valued forsaken option.

The necessary condition for the existence of cost is the presence of options. If there is no option, there is no cost. No option implies nil cost.

In the theory of production, cost reflects the value of the best alternative use of productive factors, i.e. the value which do not come into existence because existing products are preferred.

For example, in Yunan, China, the resources used up in the production of tea are not available for the production of coffee, which is the best alternative to tea. Then the value of coffee forgone is the opportunity cost of producing tea.

Opportunity cost of inputs in producing a given level of output is the benefit forgone by not using it in its best alternative use.

好似你應該去溫書，但係就用左D時間去打機
THEN你打機的機會成本就是你犧牲左溫書的時間。
又好似你本來有10蚊買飯，你用左來租漫畫，你租漫畫的機會成本就是果個本來比你食的飯盒。