A firm has $200,000 in current assets, $400,000 in long-term assets, - 576

A firm has $200,000 in current assets, $400,000 in long-term assets, $80,000 in current liabilities, and $200,000 in long-term liabilities. What is its net working capital?
A) $120,000
B) $320,000
C) $520,000
D) none of the above