阳阳家上的一题逻辑讨论

tongxun

Damages nerves in the spine do not regenerate themselves,nor even under the spur of nerve-growth stimulants.The reason is the presence of nerve-growth inhibitors in the spine. Antibodies that deactivate the inhibitors have now been developed. Clearly, the nerve repair will be a standard medical procedure in future.
Which one weakens the conclusion?

a Prevention of nerve regeneration is only a by-product of the main function in the human body of the substances inhibiting nerve growth.

b Certain nerve-growth stimulants have the similar chemical structures to those of the antibodies against nerve-growth inhibitors.

Which one is better?????
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讨论中A、B选的都有，但我认为答案应是A
题目让你WEAKEN的是结论（Clearly, the nerve repair will be a standard medical procedure in future. ）。抑制神经的再生，只是其一种副产品，用抗体将其削掉，副作用不就大了？这样的话，怎能用做a standard medical procedure 呢？
[em23]