The correct answer is: A. Valmiki National Park.
Valmiki National Park is a national park in the Indian state of Bihar. It is located in the West Champaran district, about 100 km from Patna, the state capital. The park was established in 1973 and is home to a variety of wildlife, including tigers, leopards, elephants, rhinoceroses, and deer. The park is also home to a number of endangered species, such as the swamp deer and the Bengal florican.
The park was named after Valmiki, the author of the Ramayana, one of the most important epics in Indian literature. The park is said to be the birthplace of Valmiki and is a popular pilgrimage site for Hindus.
The park is open to tourists from October to June. The best time to visit the park is during the winter months, when the weather is cool and dry.
The park can be reached by road from Patna. There are a number of hotels and resorts located near the park.
The park is a popular tourist destination and offers a variety of activities, such as jungle safaris, bird watching, and trekking.
The park is also home to a number of villages, which are inhabited by the Tharu people. The Tharu are a tribal people who have a unique culture and way of life.
The park is an important part of the Indian ecosystem and plays a vital role in the conservation of wildlife. The park is also a popular tourist destination and offers a variety of activities for visitors.
The other options are incorrect because they are not national parks in Bihar.