The managers of United Medtronics are evaluating the following four projects for the coming budget period. The firm's corporate cost of capital is 14 percent.

Project	Cost	IRR
A	$20,000	17%
B	$15,000	16%
C	$12,000	15%
D	$18,000	13%

a. What is the firm's optimal capital budget?

b. Now, suppose Medtronic's managers want to consider differential risk in the capital budgeting process. Project A has average risk, B has below-average risk, C has above-average risk, and D has average risk. What is the firm's optimal capital budget when differential risk is considered? (Hint: The firm's managers lower the IRR of high-risk projects by 3 percentage points and raise the IRR of low-risk projects by the same amount.)

c. Return to the original assumption that all projects have average risk. If United Medtronics are only approved for $30,000 towards their project budget, which project or projects would you accept? (Hint: Any money not used for a project will not receive any return).

Please show all work...thanks!