How will the right answer fit in terms of support and conclusion?

Only the right answer will be support that must be true if the conclusion is true. In simpler terms, only the right answer will support the conclusion without bringing in anything new.

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

if most individuals take a reasoned approach to getting what they want, the power of government should be less.

Political theorist: [SUPPORT]. Hence, [CONCLUSION].

The conclusion changed the subject when it brought in “a reasoned approach”. The support doesn’t tell us anything about what that might be. The right answer has to connect that wording back to what’s in the first sentence.

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

(A) …not able to convince individuals to take a reasoned approach

I like that our key phrase is in there, but the conclusion only says “if” people do it. It doesn’t say that will actually work, so this info couldn’t be “required”.

(B) Government can serve its purpose…

The author only says what that purpose is, and only in the support. The argument isn’t relying on the government actually being able to “serve its purpose”.

(C) People who take a reasoned approach…are less likely to injure other people…

Boom! This connects the new subject in the conclusion to the support. If the “reasoned approach” thing really works like the author says, this would have to be true.

(D) …will eventually be treated in the same fashion by others.

There’s no “what goes around comes around” reasoning anywhere in this argument, so this answer is pretty far off base. It’s definitely not “required” for the conclusion.

(E) The more interest people have in promoting their own welfare…

There’s no mention of “more” or less interest anywhere, so this kind of info doesn’t really fit in. Definitely not “required”.

(C) is the correct answer.

Common pattern/s in this question: I think you’ll recognize (C) as an immediate winner once you’re locked on to that new wording in the conclusion that signals the author changed the subject. You’ll have at least three or four chances to do the same thing again in every LR section.