Hyper Retail Outlets sell goods on terms of net 40. The store's average monthly sales (all on credit) are $70,000. Hyper pledges all of its receivables to the bank, which advances 80% of the receivables at a rate of 2.5% above prime. The bank also charges a 1% processing fee on all receivables pledged. Hyper borrows the full amount possible, and the current prime rate is 5%. What is the annual rate of using this source of financing for one full year?

a. 21.8% 

b. 23.5% 

c. 22.5% 

d.19.1%