Final answer:
It appears there is some confusion with the abbreviation ALDC in relation to Thomas Edison. If the question asks about his significant business ventures, Edison was 29, almost 30, when he founded the company that would later become General Electric. The abbreviation ALDC does not directly relate to his historical business establishments.
Step-by-step explanation:
The question seems to be slightly confusing as it does not specify what ALDC stands for. However, if it refers to Thomas Edison's ventures, it would most likely be referencing his involvement in creating companies that later consolidated to form General Electric. However, ALDC as an abbreviation does not directly relate to Edison's well-known businesses. Assuming ALDC is a typo or a mix-up, and referring to his major business accomplishment, Edison was 29 when he established what would become General Electric through his company Edison Electric Light Company, which might be what “ALDC” mistakenly refers to. He was not 16, 21, or 45. By the age of 30, Edison had already been involved in multiple ventures and had created the first industrial research lab in Menlo Park, New Jersey.