To solve this question, the user needs to have knowledge about the national parks in India and the districts they are located in.

A. Hazaribagh: There is a national park located in Hazaribagh, Jharkhand. The name of the park is Hazaribagh National Park. This option is correct.

B. Deogarh: There is no national park located in Deogarh district, Jharkhand. This option is incorrect.

C. Dhanbad: There is no national park located in Dhanbad district, Jharkhand. This option is incorrect.

D. Singhbhum: There is a national park located in Singhbhum district, Jharkhand. The name of the park is Betla National Park. However, the question asks for the district having "the" national park, which implies that there is only one national park in the district. As there are multiple national parks in Jharkhand, including Hazaribagh National Park, this option is ambiguous and therefore incorrect.

The Answer is: A