Final answer:
The skull is NOT a common location for Giant Cell Tumors (GCT), whereas GCTs frequently occur in the long bones of the legs and arms, spine, and pelvis.
Step-by-step explanation:
The student's question pertains to the common locations for Giant Cell Tumors (GCT). Among the choices provided, the one that is NOT a common location for GCTs is the skull. GCTs are usually found in the epiphyses (end portions) of long bones, particularly in the arms and legs such as the humerus, radius, ulna, femur, tibia, and fibula. The pelvis and spine can also be common locations for these tumors. However, while not impossible, the skull is typically not associated with GCTs, and thus, is the answer to which location is NOT common for GCT presence.