Let's look at the structure of the argument in the stimulus.
(1) It is impossible for Monroe to get elected (A) without both a fundamental shift (B) and a well run campaign (C). we can diagram this conditional statement as:
A -> B & C
(2) Monroe got elected (A)
A
(3) Therefore, there has been a fundamental shift.
B
Put together, the argument looks like this: A -> B & C A Therefore, B
The correct answer choice follows the same argument pattern.
The Park city cafe closed (A) this year. It would not have closed (A) unless it was true both that it was facing strong competition (B) and the customer base was unsatisfied (C). Therefore, we can conclude that it was facing strong competition.
(1) A (2) A -> B & C (3) Therefore, B
Let me know if this makes sense and if you have any other questions.