Functions of radius and ulna

what are the functions of radius and ulna bones ​

The radius' primary role is to provide supination and pronation by articulating with the ulna and humerus at the elbow. The lunate and scaphoid should then articulate to enable complete wrist motions.

Explanation:

They together help in rotation of the wrist.

answer; i believe that the correct answer is(d) nondisjunction during meiosis;