The primary public bus transport system in Karnataka is operated by:

The correct answer is: B) BMTC.

The Bangalore Metropolitan Transport Corporation (BMTC) is the public transport corporation that operates buses in the city of Bangalore and the surrounding areas in the Indian state of Karnataka. It is one of the largest bus corporations in India, with a fleet of over 6,000 buses. The BMTC operates over 6,000 buses on over 600 routes in Bangalore and the surrounding areas. The BMTC offers a variety of bus services, including regular buses, express buses, and night buses. The BMTC also offers a variety of fare options, including single journey tickets, monthly passes, and day passes.

The other options are incorrect for the following reasons:

• KSRTC is the Karnataka State Road Transport Corporation. It is a state-owned corporation that operates buses in the state of Karnataka. KSRTC does not operate buses in Bangalore.
• NHAI is the National Highways Authority of India. It is a government agency that is responsible for the development and maintenance of national highways in India. NHAI does not operate buses.
• KUIDFC is the Karnataka Urban Infrastructure Development Finance Corporation. It is a government agency that is responsible for financing urban infrastructure projects in Karnataka. KUIDFC does not operate buses.