The correct answer is A. aware.
Elated is the opposite of despondent, which means feeling very sad or hopeless. Enlightened is the opposite of ignorant, which means lacking knowledge or awareness in general. Therefore, the answer must be something that is the opposite of despondent but also related to knowledge or awareness. Of the four options, only aware fits this description.
B. ignorant is incorrect because it is not the opposite of despondent. C. miserable is incorrect because it is not related to knowledge or awareness. D. tolerant is incorrect because it is not the opposite of despondent.