The correct option is A Restoration
Let’s examine the sentence: “_______ of old paintings is a job for the experts.” The sentence states that experts do some kind of work on old paintings. As it talks about “old paintings” and “experts,” we can assume that the “job” is concerning renewal or revival of old paintings. So, the sentence requires the word that means “renewal” or “revival” of old stuff. Of all the options, “restoration” is the only word that means this. Hence, “restoration” is the appropriate word for the sentence. So, Option C is the correct answer.