Why do rainbows appear?
Light, droplets and your position work together.
The short answer
Sunlight bends on entering and leaving a droplet; some also reflects inside. Different colours bend differently and reach your eyes from droplets in the right directions, creating the visible arc.
An example to make sense of it
For a primary rainbow, the Sun is behind the observer and droplets are ahead. Its colours form a continuous range, although we often name seven.
How to answer
Choose the conclusion best supported by the facts and press Check. You can revise an incorrect answer and use help whenever you wish.
Preparing the case…