How will the right answer fit in terms of support and conclusion?

Only the right answer will use the same kind of support and the same kind of conclusion as the passage, and thus have the same flaw.

Highlight the main conclusion in the passage, if there is one:

clearly Frank is not an embezzler.

[SUPPORT]. But [SUPPORT]. So [CONCLUSION].

Don’t get caught up on the if-then rule. You should recognize that the author changed the subject, even if just a little bit. The conclusion is about whether Frank is actually an embezzler. The if-then rule is only about whether “the prosecutor wanted to charge” him. Those aren’t the same, so that rule doesn’t actually support that conclusion. The right answer will match all of that.

Map the wording of the answers to the wording of the passage:

(A) If Rosita knew…So she must have known…

Here the conclusion matches the if-then rule, so it’s not the same flaw. It also doesn’t have a “But..” statement contradicting the previous sentence.

(B) …so he will be in to work today.

This support doesn’t match the passage. You want the “But…” statement to contradict the condition right before it. It wants to say ‘Barry did not stay home’.

(C) If Makoto believed that he left the oven on…So obviously he did not leave the oven on.

Nice. This conclusion is about whether he actually left the oven on, but the if-then rule is about whether he “believed” he had. That’s not quite the same, in the exact same way the passage isn’t quite the same. Crystal clear, right?

(D) …She did come in early…

Here you want to catch that there’s no “But…” statement contradicting the condition in the previous sentence at all.

(E) …She is going to be fired…

Again, this doesn’t use a “But…” statement to say the condition in the previous sentence isn’t happening.

(C) is the correct answer.