Editorial: Cell-phone usage on buses and trains is annoying to other passengers.
Conclusion
That idea going around about allowing cell phones on airplanes is a bad idea.
Evidence
Cell-phone usage is annoying to other passengers in buses and trains, and in airplanes it would be even worse, because you're packed in more tightly and unable to move to any other seat.
Evaluation
They're asking us about the third sentence. It's part of the support. This suggests that telegraphed that the second sentence was the conclusion.
Goal
If we want to, we can just go to the answers, .
If you want to ask yourself now whether it's a supported premise (i.e. an intermediate / subsidiary conclusion) or if it's a regular ol' unsupported premise, you can.
Just pose the claim being asked about:
Then ask, "Why should we believe that?" and see if there are any claims that sound like an answer. Here the last two claims do sound like reasons why we should believe that cell phones on planes is even worse: you're packed in more tightly and you can't change your seat.
Since the claim we're looking at does have supporting ideas, it would be fair to call it an Intermediate Conclusion.