Which is a chemical substance that people of any age may not lawfully manufacture, possess, buy, or sell? a medicine a prescription drug an illegal drug an over-the-counter drug

An illegal drug cannot be lawfully manufactured, processed, bought, or sold by people of any age.

You did not show us the image of the burger, but i shall try to answer as best i can.  when purchasing food, always consider the ingredients as well as the person who prepared it. consider if they were hygienic people or not, in case the burger was infected with bacteria. no mortal should place an infected burger into their mouth.