求教Prep逻辑题一枚

handlebaby

请教Prep中的一道逻辑题，看不明白。。。
In Arumville, among those young children with elevated levels of lead in their blood, few live in houses containing lead-based paint, but many live in areas where vehicular traffic is heavy. These children's elevated blood-lead levels probably result from lead added to gasoline, since, although gasoline sold in and around Arumville has been lead-free sine 1990, lead from vehicle exhaust remains in the soil for many years.
Which of the following, if true, most strengthens the argument?
A. Sales of lead-based paint for use in houses was banned in Arumville in 1997.
B. Vehicle traffic in most residential areas of Arumville is heavier today than it was twenty years ago.
C. Some lead in the soil comes from deteriorating lead-based paint on the exteriors of buildings.
D. In Arumville, children's blood-lead levels typically rise during the warm summer months when children frequently play outdoors but not in the winter when children spend more time indoors.
E. If improperly carried out, the removal of lead-based paint from older houses can significantly increase the risk that children living in such house will ingest lead dust.

九段泡面高手

选D罢。  题目说：我们觉得小孩血铅超标，他们血液中的铅（lead是铅）来自汽油。尽管汽油1990年起就不让加铅了，但是铅可以 “在泥土中” 存在很多年。

D选项说小孩的血铅含量夏天容易上升，因为夏天小孩户外活动多，冬天小孩血铅就没上升。选D。

handlebaby

正解！多謝！