Interesting thoughts about (A) from both of the last two posters.
I'm not sure that "questioning the truth" is a bad match for "thinking something will likely be otherwise".
If I'm impugning the validity of someone's prediction, by suggesting an alternative prediction is more likely, is it fair to say I'm "questioning the truth" of the prediction? I think so.
But, as Griffin noticed, we have a ROCK SOLID dealbreaker in (A) with the plural 'premises'. Griffin was only saying that the columnist disagreed with the claim "more money will flow into the stock market", and the real question was
1. can we call that claim an intermediate conclusion?
2. if so, can we call it a premise in the answer choice?
For #1, I think you should rest easy knowing that LSAT will not leave us with such gray area there. I do not consider it an intermediate conclusion, because I think "these analysts conclude" a 2-part idea.
If I conclude that "tomorrow it will rain, getting the ground wet", we don't have to call the first half an intermediate conclusion and the second half the main conclusion. We can just think that my conclusion consists of a two-part thought.
Whenever there's a chain of causality, I don't think the test writers ever ask us to interpret each step along the way as an intermediate conclusion.
If they want us to recognize that another "reasoning step" is being made, they offer us keywords. So we would see something like "more money would flow into the stock market, and, hence, stock prices would continue to rise".
For #2, I don't think I've ever seen them refer to a genuine intermediate conclusion as a premise. They'll often nondescriptly refer to an IC as "an idea, supported by another idea, that lends support to something else", but I don't think they'll coyly call it a 'premise' in the narrow sense of how it supports the main conclusion.
Okay, I think we've nerded this one out sufficiently.