Q: What is the most important source of electromagnetic waves on earth?


Read this paragraph and choose the correct option from the provided answers:

The most important source of electromagnetic waves on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes.

 Choices:

- cell phones

- wireless networks

- radios

- the sun


A:
the sun