Steak is the food substance that contains the material which is needed to build muscles in the human body , but does not contain the macromolecules that provides quick energy. Steak is a type of meat which is a good source of protein and protein is the main nutrient which is responsible for the building of muscles in the human body.
Most reasonable answer is the swallowable camera one. mris and cat scans were invented in the 70s and the rest of the answers are around the 1800s or before.
