单选题 When Mr. Green retired, his son ______ the business.
A. took up B. took on C. took over D. took out

【正确答案】 C
【答案解析】短语辨析。take up意为“开始从事”；take on意为“开始雇用，承担”；take over意为“接受，接管”；take out意为“带某人出去”。根据句意，C最合适。