Films are successful as long as they
This gives us a rule that says popular ? successful We know that Quirks was popular, so by this rule we can say it was also successful. We're not trying to conclude, "This film was successful". We're trying to conclude "it was dumb to criticize this for being unrealistic". However, the correct answer also is a rule that allows us to derive that Quirks was successful, so that can't be the reason we pick (D) over this answer. It's more about the lack of a premise match here, compared with a solid premise match in (D). And it's somewhat about the meaning of "success". Correct answers to Principle questions are all about connecting the Evidence language to the Conclusion language. The detail that Quirks is "popular" is not part of the Evidence. It's just a modifier used to introduce the noun Quirks in the first sentence. In defending the movie, does out author care that it was popular? No. That's just a tangential detail. In defending the movie, our author cares that it was funny, which is the important thing for a comedy to achieve. The sort of 'success' this answer is talking about sounds more like commercially successful, whereas the sort of 'success' that (D) is talking about sounds more like artistically successful. When it comes to shutting up critics who are nitpicking at the film's lack of realism, it's more important to tell a critic that a film was artistically successful than it is to say it was commercially successful.