Prezas Company's balance sheet showed total current assets of $4,000, all of which were required in operations. Its current liabilities consisted of $900 of accounts payable, $600 of 6% short-term notes payable to the bank, and $165 of accrued wages and taxes. What was its net operating working capital?

a. $1,065

b. $1,665

c. $2,335

d. $2,935

e. $3,400