Final answer:
Flexion is a movement that decreases the angle between two bones at a joint, distinctive from extension which increases the angle. The correct statement about flexion is that it decreases the bone angle.
Step-by-step explanation:
Understanding Flexion and its Effects
During the process of flexion, the angle between two bones at a joint is decreased. This bending movement is commonly observed when you bring your forearm upward at the elbow. Conversely, extension refers to an increase in the angle between the bones, straightening the joint. It's essential to differentiate flexion from other movements such as abduction, which moves a limb away from the body's midline, and adduction, which brings it toward the midline.
In the context of your question, the correct statement about what happens during flexion is that the angle between bones is decreased (Option b).