【正确答案】 A

【答案解析】此题属于语义搭配题。commit oneself to 意为“承诺”，例如：The government claimed to commit itself to improving health care．根据上下文的意思：作为(对奖学金)回报，学生运动员则要按约定投身到他们擅长的运动项目中，故选项[A] commit themselves to，正确。选项[B] commit themselves on sth．意为“表达意见”；选项[C] commute themselves to搭配不当，应为commute for sth．(交换)；选项[D] comply themselves to 搭配不当，常用搭配为：comply with (遵守)。