This could be false. (A) says “/successful→Ignore client.” This is a confusion of the sufficient and necessary conditions of the relationship described in the stimulus.

This must be true. If we translate into lawgic, (B) says “formal ←S→ /ignore client.” As shown below, we see that there must be overlap between those two groups.

This could be false. The argument does not distinguish between different levels of attention to clients, or different likelihoods of success. We just care about whether or not someone falls into these categories at all.

This could be false. (D) takes it too far. (D) says “informal→/ignore client.” We can’t support that conditional statement. We can just say that SOME who learn informally on the job won’t ignore client wishes; we can’t make this statement about everyone who learned informally.

This could be false. Similar to (C), the stimulus does not make comparative statements. Since we don’t have any comparative evidence in the stimulus, we cannot make any comparative inferences about what the “most successful” designers do.