The correct answer is B. Nainital is a lake town in the Kumaon region of Uttarakhand, India. It is located at an altitude of 2,084 meters (6,838 feet) above sea level. The town is surrounded by hills and mountains, and the lake is a popular tourist destination.
Option A is incorrect because Nainital is not 7,500 feet above sea level. The elevation of Nainital is 2,084 meters, which is equivalent to 6,838 feet.
Option C is incorrect because Nainital is not 7,168 feet above sea level. The elevation of Nainital is 2,084 meters, which is equivalent to 6,838 feet.
Option D is incorrect because Nainital is not 6,400 feet above sea level. The elevation of Nainital is 2,084 meters, which is equivalent to 6,838 feet.