For some reason the new consultant treats his clients like idiots, talking to them like they were mentally deficient and incapable of understanding more than the simplest ideas.
Like idiots, talking to them as if they
Option (C)
“Clients ‘like’ idiots” is the correct usage as nouns are being compared. Thus, B and D can be eliminated.
Talking is an action and would require ‘as’ and not ‘like’ after it; thus, A, B, and D can be eliminated.
E fails to provide complete meaning of the sentence.