According to the passage about rainbows, where must the sun be for an observer to see a rainbow?
Read the passage: A rainbow appears when sunlight shines on falling raindrops while the sun is behind the observer. As a ray of light enters a drop, it bends, or refracts, and the different colours that make up white light bend by slightly different amounts. The light then reflects off the back of the drop and bends again as it leaves. Because each colour emerges at a slightly different angle, the colours separate into a band, with red on the outer edge of the arc and violet on the inner edge. This is also why no two people see exactly the same rainbow: the drops sending light into one person's eyes are not the same drops sending light to someone standing nearby.
Correct answer B. Behind the observer
The opening sentence says a rainbow appears when sunlight shines on raindrops while the sun is behind the observer.
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