Which bony landmark is NOT found on both the radius and ulna?

• A. Olecranon process
• B. Radial tuberosity
• C. Styloid process of the radius
• D. Interosseous crest

Answer: (A)

The question tests which forearm landmarks are shared by the radius and ulna versus those that belong to a single bone. The olecranon process is a prominent projection at the proximal end of the ulna that forms part of the elbow; the radius does not have this feature, so it is not found on both bones. In contrast, landmarks like the radial tuberosity occur on the radius, and the distal styloid process is a feature of the radius as well, while the interosseous crest refers to the ridge along the interosseous border that spans both bones where the interosseous membrane connects them. Because the olecranon is specific to the ulna, it’s the one not found on both bones.