单选题 In the author's opinion ,point-source pollution is ______.

A、 less difficult to control than non-point pollution
B、 the minor pollution source
C、 more difficult to control than non-point pollution
D、 a problem that cannot be solved

【正确答案】 A

【答案解析】细节题问按照作者的观点，地下水污染的有关情况如何。第二段讲地下水污染的形成及国家所采取的降低和杜绝污染的措施。再加Unlike point sources，these source of water pollution generally cannot be collected and treated一句可知A)为正确选项。