Assertion(A): 95% of the existing transgenic animals are mice.
Reason(R): They are important live tools for researching human disease, being used to understand gene function in context of disease susceptibility, progression and to determine responses to a therapeutic intervention.
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. Both (A) and (R) are false.