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 that the passage uses.

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

he must not have finished his thesis yet.

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

This conclusion uses a necessary condition. It says something “must” be, by combining an if-then rule with some facts. You can start eliminating answers that don’t match even that much, then see what’s left over and check details more carefully only if you have to.

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

(A) …the mayor must not have approved the proposed budget.

The conclusion says something “must” be, based on an if-then rule and some facts. All of that matches, so I’ll keep this and only check more carefully if I can’t eliminate the others pretty quickly.

(B) …Therefore, I will probably end up…

That wording doesn’t match a conclusion that says “must”.

(C) If the government or some other party had bought the processing plant…

The passage gave two conditions in its if-then rule, but this only has one.

(D) …Therefore, if the book…

The conclusion in the passage isn’t conditional like this.

(E) If Doria owes more money than she can pay back…

Same as (C), this only gives one condition in its if-then rule, but the passage had two.

(A) is the correct answer.