A group of lions is called a pride. A group of fish swim in a shoal. Teacher (choice a) and student (choice b) refer to another meaning of the word school. The answer is not (choice c) because self-respect has no obvious relationship to this particular meaning of school.
Guide and direct are synonyms, and reduce and decrease are synonyms. The answer is not choice b or d because neither means the same as reduce. (Choice c) is incorrect because increase is the opposite of reduce.