Which of the following lists the four humours identified by Hippocrates?

• A. Blood, phlegm, yellow bile, black bile
• B. Blood, phlegm, yellow bile, bile
• C. Blood, phlegm, red bile, black bile
• D. Blood, yellow bile, black bile, air

Answer: (A)

Hippocrates’ idea is that health comes from a balance of four bodily fluids. Those fluids are blood, phlegm, yellow bile (also called choler), and black bile (melancholy). This four-fluid set is the traditional list, so it matches what Hippocrates described. The other options mix in fluids that aren’t part of the theory (like air), or use terms not used in the classic list (such as red bile or a bile without a color). So the option that lists blood, phlegm, yellow bile, and black bile is the correct one.