Please, help me with this problem. Could you explain it step by step?

The HandyPlumbers Company needs a $22 000 loan for the next 30 days. It is trying to decide which of the following three alternatives to use . Alternative A: Forgo the discount on its trade credit agreement that offers terms of diSg ffs, Net 30 Alternative B: Borrow the money from Bank A, which has offered to the firm a line of credit of $28 000 for 30 days at the interest of 15% pa, payable at the end of the period. The bank also requires the commitment fee of 3% pa. on the unused part of the line of credit. Alternative C: Borrow the money from Bank B for 30 days at the interest of 12.6% p.a., payable at the beginning of the period. The bank requires a compensating balance of 5% of the face value of the loan, which means the HandyP!umbers must borrow more than the required $22 000 . Which alternative is the cheapest source of financing for the HandyPlumbers