A popular app-based ride-hailing service operating in Karnataka:

Ola
Uber
Meru Cabs
All of the above

The correct answer is D. All of the above.

Ola, Uber, and Meru Cabs are all popular app-based ride-hailing services operating in Karnataka. They offer a convenient and affordable way to get around the city, and they are all available 24/7.

Ola is an Indian multinational ride-hailing company headquartered in Bengaluru. It is one of the largest ride-hailing companies in the world, with operations in over 100 cities in India and other countries. Ola offers a variety of services, including cabs, auto-rickshaws, and bikes.

Uber is an American multinational ride-hailing company headquartered in San Francisco. It is one of the largest ride-hailing companies in the world, with operations in over 600 cities in over 60 countries. Uber offers a variety of services, including cabs, private cars, and scooters.

Meru Cabs is an Indian multinational cab aggregator company headquartered in Gurugram. It is one of the largest cab aggregator companies in India, with operations in over 100 cities. Meru Cabs offers a variety of services, including cabs, luxury cars, and SUVs.