The coastal district in Karnataka popular for its beaches:

Udupi
Dakshina Kannada
Uttara Kannada
All of the above

The correct answer is: D) All of the above.

Udupi, Dakshina Kannada, and Uttara Kannada are all coastal districts in Karnataka that are popular for their beaches. Udupi is home to the famous beaches of Malpe, Gokarna, and Agumbe. Dakshina Kannada is home to the beaches of Mangalore, Ullal, and Surathkal. Uttara Kannada is home to the beaches of Karwar, Gokarna, and Honnavar.

Udupi is a district in the Indian state of Karnataka. It is located on the west coast of India, on the Arabian Sea. The district is bounded by the districts of Uttara Kannada to the north, Shimoga to the east, and Dakshina Kannada to the south. The district has a population of over 2.5 million people. The headquarters of the district is the city of Udupi.

Udupi is a popular tourist destination. The district is home to many temples, including the famous Krishna Temple in Udupi. The district is also home to many beaches, including the beaches of Malpe, Gokarna, and Agumbe.

Dakshina Kannada is a district in the Indian state of Karnataka. It is located on the west coast of India, on the Arabian Sea. The district is bounded by the districts of Udupi to the north, Uttara Kannada to the east, and Shimoga to the south. The district has a population of over 3.5 million people. The headquarters of the district is the city of Mangalore.

Dakshina Kannada is a popular tourist destination. The district is home to many temples, including the famous Mangaladevi Temple in Mangalore. The district is also home to many beaches, including the beaches of Mangalore, Ullal, and Surathkal.

Uttara Kannada is a district in the Indian state of Karnataka. It is located on the west coast of India, on the Arabian Sea. The district is bounded by the districts of Shimoga to the east, Belgaum to the south, and Goa to the west. The district has a population of over 2.5 million people. The headquarters of the district is the city of Karwar.

Uttara Kannada is a popular tourist destination. The district is home to many temples, including the famous Mahabaleshwar Temple in Gokarna. The district is also home to many beaches, including the beaches of Karwar, Gokarna, and Honnavar.