Hey Praveen,
Interesting logic, but it's made me come to dislike the writing of this question. My guess is that the answer is C here, only because that would be the likeliest based on how these questions are written (i.e. the hope is you'll pick B, because it SOUNDS the most different). And I do see what you're saying, that the idea could be people become unable to make an intelligent decision because of some bias.
HOWEVER, the central premise around which you built this argument doesn't exist either in the stem or the answer choice, so it cannot be the issue. If that IS the issue around which the question is built, it's a deeply flawed question.
In the stem, it never says the drivers are not aware of being sleep deprived. In fact, the idea seems to be that they know they are sleep deprived, but they DO NOT understand the consequences of that fact, and drive anyway. In the example you listed, the workers may or may not be aware of the fact that they are working with noxious fumes. The important part is that they ignore the consequences of that fact, and continue working. That sounds EXACTLY like the stem, not different at all. Noxious fumes are poisonous, and to that extent, they likely would have the same effect as "being faint" would (i.e. you no longer can make an intelligent decision about your safety).
By this logic, B is still the most unlike the stem. Instead of some outside force causing the bias (schizophrenia/blood donation/fumes/alcohol/sleep deprivation), it's merely an internal bias against something (math).
To summarize, I would guess the writer of this question wants the answer to be C, because B is such an obvious trap (because it LOOKS so different). But I don't think it's well crafted enough to be convincing in that way, because B does differ in a fundamental way from the stem.
Argument?
-tommy
P.S. Also, this question was listed as a Main Point Question, which it isn't. If that was part of the way it was presented on the page it came from, it would lead me to believe even more deeply it's a flawed question.