Which root means hollow space?

• A. Crin/o
• B. Jaund/o
• C. Cav/o
• D. Thorac/o

Answer: (C)

The word part that means hollow space is cav/o. This combining form comes from a root meaning hollow or cavity, so when you see it in terms like cavity, cavitation, or cavitary, you know the word is referring to a hollow area or space inside the body.

Crin/o denotes to secrete (as in endocrine or exocrine), jaund/o relates to jaundice or yellow, and thorac/o refers to the chest/thorax. These meanings don’t align with hollow spaces, which is why cav/o is the correct root.