Q: 7 (CDS-I/2015)

When hard water is evaporated completely, the white solid remains in the container. It may be due to the presence of
1. Carbonates of Ca and Mg
2. Sulphates of Ca and Mg
3. Chlorides of Ca and Mg
Select the correct answer using the code given below :
question_subject: 
Science
question_year: 
2015
question_exam: 
CDS-I
stats: 
0,936,1936,968,936,496,472