Question

Assertion:  can be used for coagulation of  sol.

Reason:  reacts with  to give .

1. If both (A) and (R) are true and (R) is the correct explanation of (A).
2. If both (A) and (R) are true but (R) is not the correct explanation of (A)
3. If (A) is correct but (R) is incorrect.
4. If (A) and (R) are both incorrect.