To get into a top MBA program one must have five years

Here, we can break down the premises and conclusion to note that the second boldfaced portion (preceded by "so" and including a "must be") is the conclusion. Therefore choices C, D, and E are eliminated because the first portion is not the conclusion.

Between A and B, the only difference is whether the conclusion must be true or not. We know that Alexis meets two of the MBA program's requirements - the work experience and GMAT score - but we do not know whether there are other conditions that need to be met. Therefore, the conclusion is not necessarily true, and the correct answer is B.

Keep in mind in these situations that simply meeting some of the conditions necessary to the conclusion is not necessarily sufficient to make that conclusion. If you can come up with any hypothetical situations that would be consistent with the premises but counter to the conclusion, you can show that the conclusion isn't guaranteed.

For example, here we could say that, in order to be admitted, one needs to have the work experience, the GMAT score, and to have paid the application fee. That "application fee" hypothetical does not counter the premises, so it's a situation that could be true. And in that situation, Alexis may not have met all of the necessary conditions, so we can't conclude that she's going to be admitted. Because there is still room for doubt as to whether she "must be" accepted, the conclusion is not necessarily true.