How many national parks are there in Bihar?

There is only one national park in Bihar, which is the Valmiki National Park. It is located in the West Champaran district of Bihar, India. It was established in 1973 and covers an area of 899.83 square kilometers. The park is home to a variety of wildlife, including tigers, leopards, elephants, rhinoceroses, and deer. It is also home to a number of endangered species, such as the swamp deer and the Bengal florican. The park is a popular tourist destination and is known for its scenic beauty and its wildlife.

The other options are incorrect because they are not the number of national parks in Bihar.