Simple reflexes are involuntary, automatic responses to stimuli via spinal cord.

Steps:

• Define simple reflex: Quick, unconscious action bypassing brain for immediate protection.
• Assess A: Blinking is automatic eye protection from irritants.
• Assess B and C: Both are instinctive withdrawals from harm without thought.
• Assess D: Involves conscious decision-making and learned motor skills.

Why D is correct:

• Simple reflexes follow spinal cord pathways for instant response; steering requires cerebral cortex involvement for voluntary control and planning.

Why the others are wrong:

• A: Blinking is a spinal-mediated protective reflex to foreign particles.
• B: Jumping is the startle reflex, an automatic motor response to sudden stimuli.
• C: Hand withdrawal is the classic spinal withdrawal reflex to pain.

Final answer: D