Concept: This question tests your understanding of the functions of the autonomic nervous system, specifically the role of the sympathetic nervous system in regulating various body functions.

Why (B) is correct: The sympathetic nervous system is responsible for the "fight or flight" response. During this response, it increases the heartbeat rate and force of contraction to pump more blood to muscles and vital organs, preparing the body for action.

Why other options are wrong:

• (A) secretion of digestive juices: The sympathetic system generally inhibits digestive processes. The parasympathetic system stimulates digestive juice secretion.
• (C) secretion of saliva: The sympathetic system typically inhibits the secretion of watery saliva, leading to a dry mouth. The parasympathetic system stimulates watery saliva secretion.
• (D) all of these: Since options A and C are incorrect, this option is also incorrect.

Common Mistake: Students often confuse the effects of the sympathetic and parasympathetic nervous systems, especially regarding digestion and glandular secretions.

NEET Tip / Mnemonic: Remember "Sympathize with Stress" – the sympathetic system prepares the body for stressful situations (fight or flight), increasing heart rate, dilating pupils, inhibiting digestion, etc. The parasympathetic system is for "Peace and Progress" (rest and digest).

Correct Answer: (B)