Answer :
The answers are (A) (C) and (E).
The reason why (A) is a possible answer is because each side length can be multiplied by 2 to get from 6 and 3- 12 and 6.
The reason why (C) could be an answer is because if you divide 6 and 3 by 2 you would get 3 and 1.5.
The reason why (E) could be a possible answer is because if you divide 6 and 3 by 3 you would get 2 and 1.
The other answers cannot be multiplied or divided by anything to get the answers that the others have so the others are not proportional.
The reason why (A) is a possible answer is because each side length can be multiplied by 2 to get from 6 and 3- 12 and 6.
The reason why (C) could be an answer is because if you divide 6 and 3 by 2 you would get 3 and 1.5.
The reason why (E) could be a possible answer is because if you divide 6 and 3 by 3 you would get 2 and 1.
The other answers cannot be multiplied or divided by anything to get the answers that the others have so the others are not proportional.