关于逻辑问法的一个疑问

JackCai_WUDI

想知道逻辑中  weaken the conlusion 和 weaken the argument 是否有区别
我放两个例题具体一些
OG13-CR-118 It is true of both men and women that those who marry as young adults live longer than those who never marry. This does not show that marriage causes people to live longer, since, as compared with other people of the same age, young adults who are about to get married have fewer of the unhealthy habits that can cause a person to have a shorter life, most notably smoking and immoderate drinking of alcohol.
Which of the following, if true, most strengthens the argument above?
(A) Marriage trends to cause people to engage less regularly in sports that involve risk of bodily harm.
(B) A married person who has an unhealthy habit is more likely to give up that habit than a person with the same habit who is unmarried.
(C) A person who smoke is much more likely than a nonsmoker to marry a person who smokes at the time of marriage, and the same is true for people who drink alcohol.
(D) Among people who marry as young adults, most of those who give up an unhealthy habit after marriage do not resume the habit later in life
(E) Among people who as young adults neither drink alcohol immoderately nor smoke, those who never marry live as long as those who marry.
这题我当时错选A，A选项看上去确实能够加强conclusion，结婚让人们疏于运动从而影响健康
我对比了一下正选E，E则是在一个推理过程中加强。

The difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. The train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the free-wheel systems (cars, buses, aircraft), which do not have fixed routes. Thus a sufficient market for the train will not exist. Which of the following, iftrue, most severely weakens the argument presented above? (A) Cars, buses, and planes require the efforts of drivers and pilots to guide them, whereas the train will be guided mechanically. (B) Cars and buses are not nearly as fast as the high-speed train will be. (C) Planes are not a free-wheel system because they can fly only between airports, which are less convenient for consumers than the high-speed train's stations would be. (D) The high-speed train line cannot use currently underutilized train stations in large cities. (E) For long trips, most people prefer to fly rather than to take ground-level transportation. 这题也是要weaken the argument 我纠结了一下A，然后和正选C对比了一下，A是仅仅对一个结论进行削弱，而C则是在一个推理链的角度上进行削弱 我想像各位确认下，是否weaken/strengthen 一个 conclusion和argument之间是有差别（我不想自己YY出来然后就一直把自己误导下去。。。。）