Answer:
Letter A is the best option to complete the sentence:
While some people believe life on a farm would be misery, Doris was excited by the idea of waking up to sounds of nature instead of the sounds of the city.
Step-by-step explanation:
Letter A is the best option for two reasons. First, the other options provide us with words that do not fit, not helping the sentence make any sense at all. What we need to complete the sentence is either an adjective or a noun. That's not what the other options give us. Second, even if a word does fit (such as option C. applied), its meaning still needs to make sense in the context of the sentence. In that case, the only one that ticks every box is letter A.
To some people, life on a farm would be misery, but not to Doris. Misery means difficulty, distress, discomfort, problem. In other words, some people would not like the idea of living on a farm. Doris, on the other hand, was excited by it. See how it makes sense? Letter A is, thus, the best option to complete the sentence.