The correct answer is option B, Dhanbad.
Dhanbad is the largest railway station in Jharkhand, India. It is located in the Dhanbad district of the state. The station is a major hub for both passenger and freight traffic. It is connected to major cities in India such as Kolkata, Delhi, Mumbai, and Chennai. The station has a number of platforms and a large number of trains stop at the station every day.
The other options are incorrect. Ranchi is the capital of Jharkhand and is a major city in the state. However, it is not the largest railway station in the state. Bokaro is a city in the Bokaro district of Jharkhand. It is a major industrial city and is home to a number of steel plants. However, it is not the largest railway station in the state. Jamshedpur is a city in the East Singhbhum district of Jharkhand. It is a major industrial city and is home to a number of steel plants. However, it is not the largest railway station in the state.