A stockbroker earns a commission by a flat fee for each transaction as well as a fee per share. On a particular transaction, the stockbroker sold 5,000 shares to a client at a rate of $0.01 per share. The cost of the transaction totaled $57.50. Which of the following equations describes the cost of this transaction in terms of shares sold?

A.

y = 0.01x

B.

y = 0.01x + 7.5

C.

y = 0.01x + 4,999.425

D.

y = 0.01x + 5,000