As in our previous 11-Plus Verbal Reasoning Same Meaning quizzes, all you need to do is pick the answer which expresses the closest meaning to the word in CAPITALS in the question.
Words can be tricky little things at times. Some words might be similar in meaning, but there are levels of 'strength' to be considered. As an example, take a look at the following two sentences.
Whilst angry and exasperated are synonyms, exasperated is a much stronger word than angry. Likewise with loud and deafening. The more you learn about English, the better you'll be able to express yourself with similar strength synonyms!
There is also a specialist meaning in the field of electrical engineering (Answer 1) but that is unlikely to be a major issue in such a situation as this