QuestionA thief has two boxes. There are 6 coins in the box on the left and the other box is vacant. Commencing tomorrow, Nathan will put 1 coin in the box on the left and 3 in the box on the right every day. In how many days will the two boxes have the exact same number of coins? |  |
| A: 5 | B: 7 | C: 3 | D: 9 | E: 1 |