A popular two-wheeler taxi service operating in major cities of Karnataka:

Ola
Uber
Rapido
All of the above

The correct answer is D) All of the above.

Ola, Uber, and Rapido are all popular two-wheeler taxi services operating in major cities of Karnataka. Ola is the largest two-wheeler taxi service in India, with operations in over 100 cities. Uber is a global ride-hailing company that also offers two-wheeler taxis in India. Rapido is a Bengaluru-based company that offers two-wheeler taxis in over 20 cities in India.

All three companies offer a similar service, allowing users to book a two-wheeler taxi through a mobile app. The fares are generally lower than for four-wheeler taxis, and the services are often faster and more convenient.

Ola, Uber, and Rapido have all faced some challenges in India, including competition from each other and from traditional rickshaws. However, they have all become popular options for short-distance travel in major cities.