Wavelengths and Colors: Author's Purpose

Why did the author most likely write this passage?

• A.To advertise a product for sale
• B.To teach readers about light waves
• C.To entertain readers with a ghost story

Authors use examples to explain their ideas. Which sentence from the passage gives an example?

• A.A common example of light waves in action is a rainbow, which forms when sunlight passes…
• B.Light waves move through space at a speed of about 299,792 kilometers per second (or roughly…
• C.Light waves have different wavelengths, which determine their color; for instance, blue light has a shorter…