MINERAL

mineral usually is compound because it is natural substance
mineral such as sodium chloride is a compound

for the MC question
it should be C
A: if it's produced by distillation, the mineral will be separated from the water
B: mineral such as sodium chloride, of course doesn't contain heavy metal
D: distilled water and mineral are natural, so it shouldn't be a mixture of elements

多數係 compounds...
minerals 即係礦物啦~
ie the naturally-occurring form of some metals
since most metals are reactive, they do not exist in elemental form, they are usu. in the form of oxides (chlorides sometimes) and these are their natural forms, ie minerals
唔 sure 有冇, 但都有應該有 d 係 elements 的..... 呢 d 一定係好 unreactive 的.... 金好似係..... but not too sure.....