Critical Reasoning

SafeZone mosquito repellant has been shown in laboratory settings to be effective for twelve hours against the female anopheles mosquito, the only mosquito that transmits malaria. SafeZone, however, is not effective against mosquitoes that do not transmit malaria. The only instance in which SafeZone does not repel the female anopheles mosquito is if the mosquito can detect any blood, however small the amount, on a person's body. Therefore, assuming one does not have any blood on their skin before applying SafeZone, one will not be able to catch malaria for up to twelve hours.

Which of the following, if true, would argue most against the use of SafeZone in areas in which malaria is endemic?

A) SafeZone mosquito repellant has been shown to cause irritation that may result in a mild rash.
B) The culex mosquito, a different species of mosquito, is found in many areas where the anopheles mosquito is found.
C) The male Anopheles mosquito also feeds on human blood and is active at the same time as the female.
D) Once a person has contracted malaria, he or she may experience both bleeding gums and a bloody nose.
E) Some mosquitoes, after biting a person covered in SafeZone, can go on to bite a person not covered in SafeZone.

What happens with option B? It does not cast doubt on the argument?