The correct answer is: A. East Champaran
East Champaran is a district in the Indian state of Bihar. It is located in the eastern part of the state, and is bordered by the districts of West Champaran to the west, Sitamarhi to the north, Muzaffarpur to the east, and Supaul to the south. The district has a population of over 4.5 million people, and its headquarters is the town of Motihari.
East Champaran is a largely rural district, with agriculture being the main occupation of the people. The main crops grown in the district are rice, wheat, maize, and sugarcane. The district is also home to a number of industries, including sugar mills, rice mills, and paper mills.
The district is also home to a number of forests, including the Valmiki Tiger Reserve, which is the largest tiger reserve in Bihar. The reserve is home to a variety of wildlife, including tigers, leopards, elephants, and deer.
The area of very dense forest is highest in East Champaran. This is due to the presence of a number of forests in the district, including the Valmiki Tiger Reserve. The forests provide a habitat for a variety of wildlife, and also help to regulate the climate.
The other options are incorrect because they do not have as much area of very dense forest as East Champaran.