Answer : 4. "केरल"
Explanation :

1. Sabarimala Temple is a famous temple in Kerala.

2. It is dedicated to Lord Ayyappa.

2. It is the 'sacred abode of Lord Ayyappa' and one of the most important Hindu pilgrimage sites in India.

3. The temple is open to people of all religions.

4. It is open for worship only during the days of Mandal Puja, Makaravilakku, Vishu and the first day of every Malayalam month.