Evaluation of Each Option:

1. People can form caste-based associations:Reflects traditionalism and caste-based social structure, not modernization.

2. Matrimonial ads with caste/community sections: Again, this indicates continuation of traditional caste preferences, not a modern outlook.

3. People can form satsang groups through WhatsApp: Shows use of digital technology to organize and communicate—this is a clear sign of modernization in terms of media usage and connectivity.

4. People can sit together in public places: While this reflects social equality, it is more related to democratic social change, not specifically to modernization (especially technological or institutional modernization).