The answer is indeed sentence 2) Imagine how it feels to be afraid to go to the doctor for fear of plunging into debt.
The emotional rhetorical appeal is known as pathos. It's a fallacy in which the speaker's goal is to make the audience emotional about a certain topic with the intention of convincing such an audience of the speaker's point of view. In this passage, the speaker appeals to the readers emotions by having them imagine how they would feel if such a situation were to happen to them - not being able to go to the doctor for fear of being in debt afterward. The speaker's intention is to convince the readers of the importance of a policy for decent healthcare.