Concept: This question tests your understanding of reflex actions, which are involuntary, rapid, and automatic responses to stimuli, mediated by the nervous system.

Why (B) is correct: Sweating is primarily a thermoregulatory response controlled by the autonomic nervous system, but it's not typically classified as a rapid, protective reflex action in the same way as withdrawal from pain. While involuntary, its primary function is temperature regulation, not immediate protection from a harmful stimulus.

Why other options are wrong:

• (A) Salivation: This is a classic example of a reflex action, triggered by the sight, smell, or taste of food, preparing the body for digestion.
• (C) Withdrawal of hand when pinched by needle: This is a quintessential protective reflex action, preventing further injury by quickly removing the body part from the harmful stimulus.
• (D) None of these: Since sweating is not a reflex action in the context of the other options, this option is incorrect.

Common Mistake: Students sometimes confuse any involuntary action with a reflex action. Reflexes are a specific type of involuntary action characterized by their rapid, automatic, and often protective nature, involving a reflex arc.

NEET Tip: Remember the key characteristics of a reflex action: involuntary, rapid, automatic, and often protective. Think of the 'reflex arc' pathway (receptor → afferent neuron → interneuron → efferent neuron → effector).

Correct Answer: (B)