The passage tells us that "because movie reviewers have seen so many movies, their tastes are very different from and usually better informed than those of most moviegoers." We can see that this is a fact and the word "because" indicates that this is a premise as opposed to a conclusion.
E is not the correct answer because we cannot draw this as a conclusion from the premise above nor can we do so from the premise above and the first sentence of the passage. In addition to this, we can see that the final sentence of the stimulus is another premise from the use of the indicator word "yet."
The passage is arguing that "a good movie reviewer should be able to give favourable reviews of movies that are not to his or her taste." Why? Because their tastes are often different from moviegoers due to the number of movies they have seen and because "the function of movie reviewers...is to help people determine which movies they might enjoy seeing..." This makes B the correct answer.
The more you practice, the easier it will become to pick out key indicator words and map out the structure of arguments. Keep up the good work!
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