Final answer:
Ben Franklin's experiment showed that lightning is a form of electricity, but some doubt the story due to limited evidence and safety concerns.
Step-by-step explanation:
The aspect of electricity that Ben Franklin’s experiment demonstrated was B) it showed that lightning is a form of electricity. By flying a kite in a thunderstorm, Franklin was able to draw sparks from a key on the kite string, similar to the sparks produced by static electricity. This experiment established a connection between lightning and static electricity, paving the way for further understanding of electrical phenomena.
Some scientists and historians doubt this story because there is limited evidence to verify the exact details of Franklin's experiment. The story was never published by Franklin himself, but rather by others who claimed to have heard it from him. Additionally, the risks associated with flying a kite in a thunderstorm raise questions about the accuracy and safety of the experiment as it is often depicted.