【正确答案】 D

【答案解析】[命题宗旨] 形近词辨析。
[详细解答] undertake承担(工作，责任)，如：She undertook responsibility for the changes．她为这些改变承担责任。undergo接受(检查，核查)，如：She's undergoing treatment at the hospital，她在医院接受治疗。underline指“强调”，如：She underlined her disapproval by going out．她走了出去，以示她的反对。