Which Statement Most Accurately Describes the Role of the Squid

Which statement most accurately describes the role of the squid in early neurophysiology experiments?

A) To understand electrical signaling in nerves, squid giant axons must be used because they are the only animal where multiple electrodes can be used for recordings.
B) The squid giant axon makes a good model system for understanding general electrical signaling principles in all types of nervous systems.
C) Studies of the squid giant axon revealed that electrical signaling in nerves depends on the movement of fluid along the length of an axon.
D) Squid giant axons were critical in determining which molecules use ATP in transporting ions across the neuronal membrane.