Assertion (A) : Birds like pigeon have heterogametic females whereas the males are homogametic. Reason (R) : In pigeons, females have Z and W sex chromosomes whereas males have ZZ sex chromosomes.

Options :

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

3. Assertion (A) is true, but Reason (R) is false.

4. Assertion (A) is false, but Reason (R) is true.