Which combining form means clot of blood?

• A. cry/o
• B. conjunctiv/o
• C. thromb/o
• D. dist/o

Answer: (C)

The combining form thromb/o denotes a clot. It comes from a Greek root for clotting and appears in terms like thrombosis (formation of a blood clot inside a vessel) and thrombocyte (a platelet). That direct meaning—clot of blood—is why this form is the best fit. The other options refer to cold (cry/o), the conjunctiva of the eye (conjunctiv/o), or distance/away (dist/o), none of which describe a blood clot.