Net working capital is defined as:

A) current assets minus current liabilities.
B) working capital minus short-term debt.
C) current assets plus current liabilities.
D) All of the above

Net working capital is simply the difference between current assets and current liabilities. Option A represents this accurately. Option B is incorrect, as it subtracts short-term debt from working capital instead of current liabilities. Option C is also incorrect, as it adds current liabilities to current assets instead of subtracting. Therefore, the correct answer is A - current assets minus current liabilities.