The correct answer is: C. 658.27 sq km.
The district of Kullu covers an area of 658.27 sq km, which is about 5.6% of the total geographical area of Himachal Pradesh. It is the second largest district in the state after Chamba district. The district is located in the central part of Himachal Pradesh and is bounded by the districts of Mandi to the north, Shimla to the east, Lahaul and Spiti to the south, and Kinnaur to the west. The district is drained by the Beas River, which flows through the district from east to west. The main towns in the district are Kullu, Manali, and Bhuntar.
The district of Kullu is a popular tourist destination. The town of Manali is a major tourist destination and is known for its beautiful scenery, temples, and monasteries. The district is also home to the Kullu Dussehra festival, which is one of the largest and most popular festivals in Himachal Pradesh.
The district of Kullu is a beautiful and scenic district with a rich history and culture. It is a popular tourist destination and is home to the Kullu Dussehra festival.