Good discussion here. This is absolutely one of those frustrating inference questions in which the right answer is only "most" likely to be true. It's FAR from definitely true as you noted since there is nothing in the stimulus about what a party needs to do to stay in power. But Raiderblue17, you're right--since we know they are as different from each other as they are from the party in power (that they're toppling), we can infer that when these differences become apparent (which we're also told), they'll have some issues. From there, we absolutely have to make an assumption about them needing to resolve the issues to stay in power.
Raiderblue17 Wrote:A uses "as long as the party it displaces" we have no idea the truth to that.
Yes!
Raiderblue17 Wrote:C says, will not create new ideas... it seems close, but I eliminated it b/c the stimulus is about disagreements btw members of a party.
D: ALWAYS... ignored.
E: IMPOSSIBLE: IGNORED.
(C) Agree that it seems close. The problem is we don't know how promulgating a new ideology relates to the disagreements that surface after victory. And if you say, "But (B) talks about staying in power and that's not in there, either!" I'm with you. Looks like (based on some quick googling) this question caused some controversy among test-takers after the administered exam centered around this (B) or (C) issue. Ultimately, both require an assumption to be made, but (B) explicitly deals with the factions.
(D) and (E) - Careful here. Extreme terms are certainly red flags, but you do not want to "ignore" answer choices altogether because of them. As an example of why, consider (C) again. It uses "always" but in the context of saying "not always"--which just means what? Sometimes/at least once. That's not a very extreme statement, but if you just skimmed the answer choices, spotted "always" and eliminated it for this reason, you'd be knocking it out based on a false characterization of it.
(D) talks about it (always) facing opposition from the party it ousted; unsupported conclusion.
(E) You are right here that "impossible" makes this unsupported.