During the current year, assets of Ace Plumbing increased from $68,000 to $76,000, and liabilities increased from $25,000 to $28,000. If no additional capital contributions were made during the year, owner's withdrawals totaled $3,000, and expenses totaled $30,000, what was Ace Plumbing's revenue for the year? a. 538,000 b. 544,000 c. 540,000 d. $14,000 e. $36,000