Which of the following statements is correct?

a) capital rationing occurs when a company chooses to fund all positive NPV projects

b) A company typically sets no limit on the total amount of capital expenditures that it will make in the upcoming year.

c) a decreasing marginal cost of capital can occur when there is not enough internally generated cash for a firm to fund all of its positive NPV projects.

d) The equivalent annual annuity method is used to find the equivalent annual annuity for two projects with unequal lives.