A summary of selected transactions in ledger accounts appears below for Alberto's Plumbing Services for the current calendar year-end. Common Stock 1/1 6,500 Retained Earnings 3,500 12/31 15,000 12/31 Dividends 1,650 12/31 1,850 3,500 3/30 9/30 Net income for the period is a. $21,500 b. $25,000 c. $15,000 d. $3,500