Saddle joints have concave and convex surfaces. name the two bones of the hand that articulate to form a saddle joint. a. the trapezium of the carpal bone and the thumb's metacarpal. b. the scaphoid of the index finger and the triquetrum of the middle finger. c. the trapezium of the ring finger and the capitate of the fourth finger. d. the scaphoid of the middle finger and lunate of the index finger.

Option (A).

Explanation:

Saddle joint is a type of synovial joint and also known as sellar joint. These joints are present in thumb, shoulder and inner ear.

The bone has one part concave inward and other part is convex outward. This bone can articulate with thumb's metacarpal and trapezium of the carpal bone. Saddle joints show abduction and adduction movements.

Thus, the correct answer is option (A).

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