Which combining form means joint?

• A. Arthr/o
• B. Ather/o
• C. Col/o
• D. Myel/o

Answer: (A)

arthr/o is the combining form that means joint. In medical terms, combining forms link a root to a suffix, and arthr/o specifically denotes a joint, allowing words like arthritis (joint inflammation) or arthroplasty (surgical repair of a joint). The other options refer to different body parts or structures: ather/o means fatty plaque in arteries, col/o means the colon, and myel/o means the spinal cord or bone marrow. Because arthr/o is the one that targets joints, it is the correct choice.