I agree with @"Creasey LSAT" in that you'd probably be better off using your intuition to get this one. The question stem is a bit too dense in information and lacks clear conditional language. The answers, however, do have clear conditional language which can guide you to correct choice.
Here's what A) has to say: Helpful --> Laudable Wrong --> Led person to believe...
The question stem says "It would be laudable if the Jacksons passed along... (i.e. helpful)". Therefore, they fulfilled the sufficient condition in the first part of answer choice A (helpful --> laudable).
The Jacksons also negated the necessary condition in the second statement (they didn't lead Sara to believe...), so they were not wrong.
There's your pseudo-sufficient assumption/principle. Hope that helps.
Comments
Here's what A) has to say:
Helpful --> Laudable
Wrong --> Led person to believe...
The question stem says "It would be laudable if the Jacksons passed along... (i.e. helpful)". Therefore, they fulfilled the sufficient condition in the first part of answer choice A (helpful --> laudable).
The Jacksons also negated the necessary condition in the second statement (they didn't lead Sara to believe...), so they were not wrong.
There's your pseudo-sufficient assumption/principle. Hope that helps.