An antibiotic, Penicillin, is cleared from the body through different routes. The rates of excretion of penicillin in various body fluids and elimination pathways are shown in the graph below.
Which of the following, A to D, correctly explains the different rates of penicillin excretion in each body fluid?
Penicillin is highly soluble in water.
Penicillin is extremely lipid-soluble.
The kidneys are less efficient at excreting polar compounds than the lungs.
Penicillin is easily vaporized at normal body temperature.