I'm afraid the question is either not phrased correctly or the answers too ambiguous to helpful.
By the options that are offered, I suspect that the correct question should have been:
"The jacket is not ON sale." To be "on sale" means to be offered at a discount. If this were the case, then the answer would be C) full price. Full price means that there is no discount on the price of the item.
However, to say that "the jacket is not FOR sale" means that you are not selling the jacket at all. You are not selling at a discount or at full price. The reasons you have are that the jacket is A) scruffy, B) choosy C) full price or D) a bargain.
Since they are not selling it, then it cannot be C or D. And jackets aren't people so they can't be B) choosy. However, if a jacket is scruffy, it might be a good reason for not selling it. But in my opinion, if a jacket is scruffy, I would just sell it at a discount. It doesn't seem a good enough reason to not sell a jacket.
So, I go back to my original theory. The question is phrased incorrectly and should actually be:
"That jacket is not ON sale. It is... D) full price."