Which part of the skeleton is made up of the limbs and girdles attaching them to the axial skeleton?

The appendicular skeleton comprises the bones of the limbs, including the arms and legs, as well as the associated girdles that connect these limbs to the axial skeleton. The axial skeleton, in contrast, consists of the skull, vertebral column, and rib cage, providing the central structure of the body and supporting the head and trunk. The endoskeleton refers generally to the internal skeletal structure of vertebrates but does not specifically denote only the limb bones and girdles. The pectoral girdle, while a part of the appendicular skeleton, specifically refers to the structure that connects the upper limbs to the body and does not encompass the entirety of the limb bones. Therefore, the correct answer focuses on the comprehensive group of limb-associated structures, confirming that the appendicular skeleton is the part responsible for these connections.