HELP!　GWD CR 题

Q: Guidebook writer: i have visited hotels throughout the country and have noticed that in those built before 1930 the quality of the original carpentry work is generally superior to that in hotels built afterward. Clearly carpenters working on hotels before 1930 typically worked with more skill, care, and effort than carpenters who haev worked on hotels subsequently.

Which of the following, if true, most seriously weakens the guidebook writer's argument?

(A) The quality of original carpentry in hotels is generally far superior to the quailty of original carpentry in other structures, such as houses and stores

(B) Hotels built since 1930 can generally accomodate moer guests than those built before 1930

(C) The material available to carpenters working after 1930 were nto significantly different in quality from the materials available to carpenters working after 1930.

(D)The better quality of original carpentry in a building, the less likely that building is to fall into disuse and be demolished

(E)The average length of apprenticeship for carpenters has declined significantly since 1930.

The answer is (D)--->WHY???

I know that A, B, E are out of scope, and C is strengthen,

but D looks like strengthening to me too!

PLEASSE HELP!!

TKS!

CC

D的意思是说那些木工工作质量好的建筑被保留下来了（而不好的就损毁拆除了）

所以就是拿现在所有的carpentry work和过去better quality of original carpentry在比较，weaken了