单选题 The author mentions Kleck, kott, and Bellesiles mainly to ______.

A、 illustrate the influence they have on the issue of gun control
B、 refute the claim that private ownership of firearms will deter violent crimes
C、 support the thesis that gun ownership leads to more violence
D、 demonstrate why research methods should be improved in the study of the gun ownership history

【正确答案】 D

【答案解析】文中提到Kleck 和 Lott是支持私人拥有枪支的，认为这会阻碍犯罪。而Bellesiles是反对私人配枪的，认为正是此导致了更多的犯罪。所以B、C都不对。作者提到此三人是指出他们的错误从而表明采用新的研究方法的重要性。所以正确答案是D。