The district in Karnataka bordering the state of Kerala:

Udupi
Dakshina Kannada
Kodagu
Uttara Kannada

The correct answer is: B) Dakshina Kannada

Dakshina Kannada is a district in the Indian state of Karnataka. It is located in the southwestern part of the state, bordering the state of Kerala. The district is known for its beautiful beaches, temples, and wildlife sanctuaries. The capital of Dakshina Kannada is Mangalore.

Udupi is a district in the Indian state of Karnataka. It is located in the southwestern part of the state, bordering the state of Kerala. The district is known for its temples, beaches, and religious tourism. The capital of Udupi is Udupi.

Kodagu is a district in the Indian state of Karnataka. It is located in the southwestern part of the state, bordering the state of Kerala. The district is known for its hills, forests, and coffee plantations. The capital of Kodagu is Madikeri.

Uttara Kannada is a district in the Indian state of Karnataka. It is located in the northwestern part of the state, bordering the state of Goa. The district is known for its beaches, temples, and wildlife sanctuaries. The capital of Uttara Kannada is Karwar.

The district in Karnataka bordering the state of Kerala is Dakshina Kannada.