Critical Reasoning

Brushing your teeth regularly, no matter which toothpaste you use, will reduce your chances of tooth decay. Scientists have concluded that, when you brush, you reduce tooth decay by removing the film of plaque that forms on teeth and gums. So, you can forget about fluorides: brush your teeth carefully and say goodbye to cavities.
Which one of the following is a criticism of the reasoning in the argument?
(A) Brushing with fluoride toothpaste has been shown to reduce tooth decay.
(B) The fact that brushing will reduce tooth decay does not show that fluorides are of no value.
(C) Few people adequately remove plaque by brushing.
(D) People have plaque on their teeth most of the time.
(E) Scientists have been wrong about fluorides.

Is it B?

Its B. Answer please

IMO: B.

What is the OA?

Thanks.