Final answer:
The occipital bone contains the foramen magnum, the large opening that allows the spinal cord to pass through, and therefore is the correct answer to the student's question.
Step-by-step explanation:
The student asked which bone has a foramen that encircles the superior aspect of the spinal cord. The correct answer is C) occipital bone. The occipital bone features the foramen magnum, which is the large opening that allows the spinal cord to emerge from the skull and connect to the brain. This foramen is indeed the one that encircles the superior aspect of the spinal cord, and it is located at the base of the skull. The occipital bone forms the posterior part of the skull and is crucial for supporting the skull on the vertebral column with its occipital condyles.