Consumer advocates argue that the coating found on non-stick cookware contains harmful chemicals that are released into the air when the cookware is heated above a certain temperature. The manufacturer of the cookware acknowledges this hazard but assures consumers that the temperature threshold is much higher than would ever be needed for food preparation and therefore no special precautions need be taken in using the cookware.

Which of the following, if true, would cast the most serious doubt on the claims of the manufacturer?

(A)The chemicals released by the coating can linger in the air for days
(B)Empty cookware left on the flame often reaches exceptionally high temperatures.
(C)Several consumers have already claimed illness as a result of using the cookware.
(D)The manufacturer did not test the cookware for this phenomenon until consumer advocates brought the issue to its attention.
(E)There are effective non-stick coatings that do not release toxins when heated.

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Please can anyone tell me why the actual answer is B? My reasoning for it not being a contender was because "exceptionally high temperatures" doesnt have to mean temperature near the threshold.Im a bit confused.
Thanks