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.
An optimist is a person whose outlook is cheerful. A pessimist is a person whose outlook is gloomy. The answer is not (choice b) because a pessimist does not have to be mean. (Choices c) and d are incorrect because neither adjective describes the outlook of a pessimist.
EXAMIANS