State of unconsciousness in which a person is unable to respond to any change in the environment including pain?

• A. Sleep
• B. Stupor
• C. Coma
• D. Vegetative state

Answer: (C)

Coma is a deep level of unconsciousness where the person cannot be awakened and does not respond purposefully to any stimuli, including pain. In a coma, there is no purposeful movement, no vocalization, and no awareness of the surrounding environment, even when strong stimuli are applied. This contrasts with sleep, where a person can be awakened and will respond to stimuli; with stupor, arousal occurs only with vigorous or repeated stimulation and responses are limited; and with a vegetative state, there may be wakefulness (such as eye opening) but no conscious awareness. So the description of complete unresponsiveness to changes in the environment and to pain fits coma.