In this Principle (Strengthen) we are being asked to strengthen Jamie's conclusion that "The airline is not morally obligated to pay Arnold any compensation." Let's start by breaking down the stimulus:
Arnold had a confirmed reservation. He was rebooked to a later flight. Arnold missed a business meeting because of this. Arnold's original flight was canceled due to bad weather.
We need an answer choice that, when applied to these circonstances, allows us to justify the idea that the airline is not morally obligated to pay Arnold any compensation. Answer choice C says "only if the passenger would not have been forced to take a later flight had the airline not overbooked the original flight" which taken together with the Question Stem (an airline is morally obligated to compensate a passager) can be diagrammed as: MOC --> FLF* or the contrapositive FLF --> MOC*. (FLF = forced to take later flight had the airline not overbooked the original flight and MOC = morally obligated to compensate). If we look at the facts above, we can determine that Arnold would have been forced to take a later flight anyways (FLF). So we have satisfied the sufficient condition of the contrapositive, which allows us to prove the conclusion *MOC or that the airline is not morally obligated to compensate Arnold.
Answer choice E states: "even if the passenger would still have been forced to take a later flight had the airline not overbooked the original flight." Keep in mind that "even if" constructions are tricky in conditional logic. They neither introduce a necessary nor a sufficient condition, rather, "even if" introduces something that is not a necessary condition. So we could reword answer choice E to be saying : "It is not necessary to be forced to take a later flight had the airline not overbooked the original flight, for an airline to be morally obligated to compensate a passager." In other words, airlines are morally obligated to compensate passagers regardless of whether they would have be or would not have been forced to take a later flight anyways, which doesn't strengthen Jamie's conclusion.
I hope this helps. Feel free to follow-up if this is still unclear.
