The correct answer is: C. Current assets + Prepaid expenses
Liquid assets are assets that can be quickly converted into cash. They include cash, cash equivalents, short-term investments, and accounts receivable. Prepaid expenses are expenses that have been paid in advance but have not yet been incurred. They are not considered liquid assets because they cannot be converted into cash immediately.
Option A is incorrect because it subtracts stock from current assets. Stock is not a liquid asset because it cannot be converted into cash quickly.
Option B is incorrect because it adds stock to current assets. Stock is not a liquid asset because it cannot be converted into cash quickly.
Option D is incorrect because it does not include prepaid expenses. Prepaid expenses are considered liquid assets because they can be converted into cash quickly.