Answer the following question given this paragraph: 

“Neon” signs are familiar examples of gas discharge tubes. However, only signs that glow with the red-orange color seen in the figure are actually filled with neon. Signs of other colors contain different gases or mixtures of gases.


Q: What colors in a neon sign represent real neon?

 Choices:

- purple, blue

- blue, green

- yellow, white

- red, orange

A:
red, orange
