tuck = drop or fold?

[Linh Bui Hoang]

I waver between A and D in the following multiple-choice question, which requires to find the word closest in meaning to the underlined word
The young boy tucked the coin into his pocket.
A.Dropped B.grabbed C.opened D.folded
My teacher said the answer was D but I think folding coins is impossible. If it were paper-money in the sentence, I would choose D. So I would rather choose A.

[Jamie (K)]

D is the wrong answer, because, as you say, you can't fold a coin. You also don't fold a pocket.

In my opinion, all four of the answers are wrong. In this case, "tuck" means that the boy pushed the coin very far down into his pocket. He didn't just drop it, but used his hand to push it securely into his pocket.