Concept: Formation of rainbow
Primary rainbow:
• One internal reflection
• Red on top, violet at bottom
Secondary rainbow:
• Two internal reflections
• Colors reversed
• Less bright
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Step 1: Mechanism • Light enters droplet → refraction
• Undergoes two reflections • Comes out after second refraction
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Step 2: Check options • (B) Wrong → secondary is dimmer
• (D) Wrong → color order reversed
• (C) Wrong → no double refraction
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Final Answer:
\[
\boxed{\text{Two internal reflections}}
\]