Which of the following terms describes the straightening of a joint, rather than the bending?
a.
flexion
b.
hyperextension
c.
extension
d.
none of the above

Explanation:

We can classify motion of a joint as: flexion, hyperflexion, extension and hyperextension. We can define all of them.

Flexion refers to the bending of a joint in such way that the bones involved are pulled close together. Moreover, hyperflexion is when the flexion movement is beyond the normal range, this movements often result in injuries.

Extension refers to the opposite movement of flexion, refers to the straightening of a joint, a extension movement increase the distance between the bones involved, increasing the angle between them. So, hyperextension happens when the extension movement is more than the normal motion range. As hyperflexion, this hyper movement also often results in injuries.

Therefore, the term that describes the straightening of a joint is extension, they comprehend the same type of movement on joints.