Answer: Option C
Step-by-step explanation: In simple words, cost of capital refers to the amount of return that the investor are expecting for tasking the risk of investing in the company. In other words, it is the amount the company has to offer in return to the investors for attaining the capital from the market.
Often the cost of capital is used to evaluate the profitability of the project, that is, if the return in project is higher than the cost of financing it should be taken by the company.
However there are other component while evaluating a project that is risks associated with it. Risk of every projects is different from the other and hence only those project should be evaluated on the basis of cost of capital that is similar to the company's average.