单选题 Colin married my sister and I married his brother, ______ makes Colin and me double in-laws.
A. what B. which C. that D. it

【正确答案】 B
【答案解析】[解析] 本题的测试点为非限制性定语从句。非限制性定语从句一般用逗号与主句隔开，而且不能用that。本句中which的先行词是整个主句，全句意为：“柯林娶了我姐姐，我嫁给了他的弟弟，这使我们亲上加亲。”