I think the answer would be d but not 100% sure
Since the beaker was heated we can asume that only magnesium cloride is left in the beaker, therfore the difference between the beaker with magnesium chloride and the empty beaker give the mass of magnisium chloride:
Answer:
- metal sulfate
- metal sulfate
- copper sulfate
- copper nitrate
- copper chloride
- copper phosphate
- hydrochloric acid, water
- Potassium, sulfuric acid, water
(Correct me if I am wrong)