关于解释题的无关项问题

深高金的zkk

Nitrogen dioxide is a pollutant emitted by automobiles. Catalytic converters, devices designed to reduce nitrogen dioxide emissions, have been required in all new cars in Donia since 1993, and as a result, nitrogen dioxide emissions have been significantly reduced throughout most of the country. Yet although the proportion of new cars in Donia’s capital city has always been comparatively high, nitrogen dioxide emissions there have showed only an insignificant decline since 1993.

Which of the following, if true, most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia’s capital city?
AMore of the cars in Donia’s capital city were made before 1993 than after 1993.
BThe number of new cars sold per year in Donia has declined slightly since 1993.
CPollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993.
DMany Donians who own cars made before 1993 have had catalytic converters installed in their cars.
EMost car trips in Donia’s capital city are too short for the catalytic converter to reach its effective working temperature.
正确答案是E

这道题我知道主要的矛盾是“别的地方政策有效”vs”首都的城市政策不凑效“。我总觉得ABCD好难排除，总是不能一下子就排除掉。各位NN能不能帮我捋一下逻辑链呀。

长丝弓

楼主，ABCD排除如下
A新车相对少一些不一定是insignificant
B未说到涉事城市首都
c无关污染不在讨论范围内
D是削弱涉事城市首都没有显著改善的