During 2018, the cash flows related to Global Data, Inc.'s lending and borrowing activities are summarized as follows:

Cash lent to borrowers	$	132,600
Payment to retire bonds payable	$	367,500
Proceeds from borrowing at bank (note payable)	$	220,500
Interest received from borrowers	$	31,500
Interest payments made on bonds payable	$	42,000

If interest receivable was $6,300 at December 31, 2017, and is $10,500 at the end of 2018, interest revenue reported in Global Data's income statement for 2018 must have been:

Select one:

a. $16,800.

b. $21,000.

c. $35,700.

d. $4,200.