选A,I would like to buy one made in Shanghai.我想买个上海制造的汽车.没有特指是哪一辆.
that的意思是那个,特指,我想买那个上海制造的车,但也需要与one连用,如果是i would like to buy that one made in Shanghai.那就也是对的.想象一下情景,这与我们说汉语时的道理也是一样的.