The concentration of a certain medication in a patient's bloodstream, in milligrams per liter, , hours after administration, is modeled by the function . The graph of is shown. What is the best interpretation of the -intercept of the graph in this context?
The initial concentration of the medication.
The time it takes for the medication to be completely eliminated from the bloodstream.
The time when the concentration of the medication reaches 20 mg/L.
The time when the medication's concentration drops to a critical minimum level of 20 mg/L.
