逻辑大全一题，求问

纯斓梦

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.（A）

(E) Deactivating the substances inhibiting nerve growth for an extended period would require a steady supply of antibodies.
我用排除法，选择了A，但是真的没看懂A选项是什么意思，求指教~

qiaowin88637

事实：Damaged nerves in cord do not regenerate naturally, nor regenerate under the spur of stimulants, 因为The presence of inhibitors in cord. Antibodies that deactivate those inhibitors have now been developed
推理： Nerve repair will be a standard medical procedure in the foreseeable future.
【事实推理型】事实A→推理B，需要直接推翻B
取非：Nerve repair will not be a standard medical procedure in the foreseeable future.

(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.
长句简化：Prevention of the regeneration is a main function in the human body of the substances which inhibit nerve growth
换句话说，即使你阻止了inhibitors in cord，也不能阻止那些substances继续阻碍再生
（inhibitors和substances是两个平行阻碍再生的因素）

纯斓梦

哦，懂了，谢啦！