Mary has sold 4 8⁄12 liters of soft drink on Monday, 3 6⁄14 liters of soft drink on Tuesday and 5 4⁄6 liters on Wednesday. The number of liters she has sold in total are

• A. 13 16/21
• B. 14 16/21
• C. 15 16/21
• D. 17 16/21