The appendicular skeleton includes

Step 1: Analyze the question The question asks which bones make up the appendicular skeleton.

Step 2: The concept The human skeleton has two main divisions:

• Axial skeleton forms the central axis of the body. It includes the skull, vertebral column, ribs and sternum.
• Appendicular skeleton includes the limbs (appendages) and the girdles that attach them to the axial skeleton. It includes the pectoral (shoulder) girdle, the pelvic (hip) girdle, the forelimbs (arms) and the hindlimbs (legs).

Step 3: Check each option

• A. Pectoral and pelvic girdles. Both girdles belong to the appendicular skeleton. This is correct.
• B. Forelimbs, skull and pectoral girdle. The forelimbs and pectoral girdle are appendicular, but the skull is axial, so this option is wrong.
• C. Lungs and ribs. The lungs are organs, not part of the skeleton, and the ribs are axial. This is wrong.
• D. Skull and the vertebral column. Both are axial. This is wrong.

Step 4: Answer Option A is the only one in which every item belongs to the appendicular skeleton.

Exam tip: Remember "Appendicular = Appendages". Think of the limbs and the girdles that hold them. The axial skeleton is the "axis", the head and trunk (skull, spine, ribs, sternum). If an option contains the skull, vertebrae or ribs, it is not purely appendicular.