Three of the following pairs of the human skeletal parts are correctly matched with their respective inclusive skeletal category and one pair is not matched. Identify the non -matching pair. 

• Pairs of skeletal parts	Category
  Sternum and ribs	Axial skeleton

• Pairs of skeletal parts	Category
  Clavicle and glenoid cavity	Pelvic girdle

• Pairs of skeletal parts	Category
  Humerus and ulna	Appendicular skeleton

• Pairs of skeletal parts	Category
  Malleus and stapes	Ear ossicles