These four ways are actually four stages that medicines undergo within the human body.
After a medicine is administered, it is absorbeb into the bloodstream. The circulatory system then distributes the drug throughout the body. Then it is metabolized by the body. The medicine and its metabolites are then excreted.
This could vary as any health professional should enjoy working with the population they choose to work with. Despite that, it seems like most likely answer would be children.
