Which of the following is NOT a standard type of bone?

• A. Long bones
• B. Short bones
• C. Cartilage bones
• D. Irregular bones

Answer: (C)

Bones are categorized by shape: long, short, flat, and irregular (with sesamoid bones sometimes listed separately). Cartilage, however, is a distinct connective tissue, not bone. Bone can form from cartilage during development, but a category called “cartilage bones” isn’t a standard bone type. So the option describing cartilage as a bone isn’t a valid bone category, while the others—long, short, and irregular—are standard bone shapes.