Question

thomas edison invented a phonograph and one of the first motion picture cameras, but his most important invention was much simpler. what was it?
○ the radio
○ the toaster
○ the zipper
○ the working light bulb

Explanation:

Thomas Edison is well - known for inventing the practical incandescent light bulb. He made improvements to existing light - bulb designs to create a working, long - lasting light bulb that was a major advancement. The radio, toaster, and zipper were not his most important inventions.

Answer:

the working light bulb