Hi I am having a tough time with this accounting homework problem, can you solve it and please explain how to answer it?? Thanks!

The following selected account balances appeared on the financial statements of the Washington Company:

Accounts receivable, Jan. 1 $13,000

Accounts receivable, Dec. 3 19,000

Accounts payable, Jan. 1 4,000

Accounts payable, Dec. 31 7,000

Merchandise inventory, Jan. 1 10,000

Merchandise inventory, Dec. 31 15,000

Sales 56,000

Cost of merchandise sold 31,000

The Washington Company uses the direct method to calculate net cash flow from operating activities.

Cash payments for merchandise were

a.$39,000b.$23,000c.$33,000d.$29,000