Which combining form denotes hardening or sclerosis?

• A. aut/o
• B. later/o
• C. scler/o
• D. cutane/o

Answer: (C)

The concept here is recognizing the combining form that means hardening. The combining form scler/o directly denotes hardening or sclerosis, which is why it is the correct choice. You’ll see it in terms like scleroderma (hardening of the skin) and arteriosclerosis (hardening of arterial walls). The other roots don’t convey hardening: aut/o means self, later/o relates to the side, and cutane/o means skin.