Sleeping under a tree is not advisable at night, since photosynthesis does not occur, oxygen is not being produced by the trees. In addition to this, the trees continue respiring thereby causing the amount of carbon dioxide to be increased and the amount of oxygen to be reduced.

The Eastern Command of the Indian Navy is headquartered in Visakhapatnam.

Therefore, the correct answer is:

(B) Visakhapatnam

The Eastern Command of the Indian Navy is headquartered in Visakhapatnam. Visakhapatnam, also known as Vizag, is a major port city on the southeast coast of India. The Eastern Naval Command (ENC) plays a crucial role in the maritime defense and security of the eastern part of India. It is responsible for overseeing and coordinating naval operations, exercises, and deployments in the Bay of Bengal and the eastern Indian Ocean region. The command is strategically located to address security challenges and ensure the protection of India's maritime interests in the eastern seas.