Assertion(A): Viruses grown in the presence of radioactive phosphorus contained radioactive DNA but not radioactive protein.
Reason(R): Protein contains phosphorus but DNA does not.
Choices for Assertions and reasons:
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.