Final answer:
The letter C indicates the mandibular fossa of the temporal bone (option C).
Step-by-step explanation:
The letter C indicates the mandibular fossa of the temporal bone. The mandibular fossa is a key feature of the temporal bone in the human skull, that serves as the point of articulation for the mandible, or lower jaw. This fossa is described as a deep, oval-shaped depression located on the external base of the skull, just in front of the external acoustic meatus, and is part of the temporomandibular joint which facilitates the opening and closing movements of the mouth.
Hence, the answer is option C.