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 working light bulb
○ the toaster
○ the radio
○ the zipper

Explanation:

Thomas Edison is well - known for inventing the working light bulb. The radio was invented by Guglielmo Marconi, the toaster was invented by Charles Strite, and the zipper was invented by Whitcomb Judson. So the correct option is the one related to the working light bulb.

Answer:

A. the working light bulb