Concept: The phrasal verb "give in" means to stop resisting or to surrender to something.Explanation:"Give in" is used when someone stops fighting or arguing and accepts defeat or yields to a desire. In the sentence, people find it difficult to stop resisting temptation, so "in" fits correctly. The other options do not form the correct phrasal verb: "give away," "give over," and "give off" have different meanings. Thus, the completed sentence is: "Some people find it difficult not to give in to temptation."Answer: C. in