Final answer:
The correct order from dorsal to ventral of the organs is B. Notochord, nerve cord, gut. The notochord is a stiffening rod, the dorsal hollow nerve cord becomes the central nervous system, and the gut encompasses the digestive organs.
Step-by-step explanation:
From dorsal to ventral, the correct order of these organs is B. Notochord, nerve cord, gut.
The notochord is an elongated, flexible rod made of a material similar to cartilage. In chordates, it is located between the dorsal nerve cord and the gut, and it provides stiffness to counterbalance the pull of muscles. The dorsal hollow nerve cord develops from a plate of ectoderm that rolls into a hollow tube during embryonic development. It is situated dorsally to the notochord in chordates, eventually developing into the brain and spinal cord, comprising the central nervous system. Finally, the gut represents the digestive organs, situated ventrally to the other two.