Final answer:
The Transformers come from the planet Cybertron, which is option C. The other options are not correct as they relate to different characters or series, with Megatron being a character, Melmac being a different show's planet, and Cyberdyne being a corporation.
Step-by-step explanation:
The Transformers are a popular franchise involving characters that can change from robots to vehicles or other machinery. The planet they originate from is an integral part of their storyline. When asked where the Transformers come from, the correct answer is C. Cybertron.
Option A, Melmac, is the home planet of ALF from the TV show of the same name. Option B, Cyberdyne, is a corporation from the 'Terminator' series, which is unrelated to the Transformers universe. Option D, Megatron, is actually the name of a character within the Transformers series, not a planet.
Therefore, the factual answer to the question is that the home planet of the Transformers is Cybertron.