Critical Reasoning

Damaged nerves in the spinal cord do not regenerate themselves naturally, nor even under the spur of nerve-growth stimulants. The reason, recently discovered, is the presence of nerve-growth inhibitors in the spinal cord. Antibodies that deactivate those inhibitors have now been developed. Clearly, then, nerve repair will be a standard medical procedure in the foreseeable future.

Which of the following, if true, casts the most serious doubt on the accuracy of the prediction above?
(A) Prevention of the regeneration of damaged nerves is merely a by-product of the main function in the human body of the substances inhibiting nerve growth.
(B) Certain nerve-growth stimulants have similar chemical structures to those of the antibodies against nerve-growth inhibitors.
(C) Nerves in the brain are similar to nerves in the spinal cord in their inability to regenerate themselves naturally.
(D) Researchers have been able to stimulate the growth of nerves not located in the spinal cord by using only nerve-growth stimulants.
(E) Deactivating the substances inhibiting nerve growth for an extended period would require a steady supply of antibodies.

IMO B

another one for B ... rest seems out of scope.

B IMO. OA plz.

i think the answer should be A

as we need to weaken the conclusion that the nerve repair would be the standard medical procedure in the future, when the antibiotic to deactivate the actions of the inhibitor develop.

so to cast doubt on this prediction the answer choice A clearly states that prevention of the regeneration of damaged nerves is only the by-product of the main function of inhibitor in the human body. Therefore, there is the possibility that the main function of inhibitor in human body is of much value, so we can not easily predict that the above metod would become standard procedure............

hope this will heelp.........

it is B

Well I feel B is the answer. I guess I'm right. If some expert could