Which of the following is part of the axial skeleton?
arm
pectoral girdle
pelvic girdle
skull

The bone that is part of the axial skeleton is the skull. The axial skeleton refers to the part of the skeleton that consists of the bones of the head and the trunk of a vertebrate. In the human body, there are 80 bones found in the axial skeleton composed of six parts: the skull bones, the ossicles of the middle ear, the hyoid bone, the rib cage, sternum, and the vertebral column. 

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