The Following Questions Refer to the Description Below

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker, and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
-Terry takes the body of the snakelike organism and slices it open along its dorsal side. If it is a hagfish, what should Terry see?

A) a well-developed series of bony vertebrae surrounding the spinal cord
B) a well-developed series of cartilaginous vertebrae surrounding the spinal cord
C) a tube of cartilage (surrounding the notochord) with dorsal projections on both sides of the spinal cord
D) a notochord, located underneath the spinal cord