Swinnerton Clothing Company's balance sheet showed total current assets of $1,400, all of which were required in operations. Its current liabilities consisted of $575 of accounts payable, $300 of 6% short-term notes payable to the bank, and $145 of accrued wages and taxes. What was its net operating working capital that was financed by investors?

Select the correct answer.

a. $671

b. $680

c. $676

d. $667