Question

what is a notochord? an organ that develops into fins and a tail the beginning of the skin that eventually surrounds the organism in scales a flexible, longitudinal rod between the digestive tract and the nerve cord

Explanation:

The notochord is a key embryonic - stage structure in chordates, defined as a flexible rod - like structure located between the digestive tract and nerve cord.

Answer:

C. a flexible, longitudinal rod between the digestive tract and the nerve cord