the doctor told me to eat more ()because it is good for my b

A orange 前面有more,所以不能选,应该是oranges
B vegetables 后面it is good 应该是不可数名次,C fish.
再问： it is good for your health to eat more vegetables.
再答： 问题里的it 指的是（）里的东西，而不是“多吃...”，要不就没法选了。