Final answer:
The letter indicating the foramen magnum of the occipital bone is (C). The foramen magnum is a key feature of the occipital bone, providing passage for the spinal cord and vertebral arteries.
Step-by-step explanation:
The letter that indicates the foramen magnum of the occipital bone is option (C).
The foramen magnum is a large opening in the occipital bone of the skull, which allows for the passage of the spinal cord as it exits the skull and the vertebral arteries to enter the cranium.
The occipital bone itself forms the posterior part of the skull and the base of the cranial cavity.
On either side of the foramen magnum, there are oval-shaped structures known as occipital condyles, which form joints with the first cervical vertebra, aiding in supporting the skull atop the vertebral column.