In the experiment on stimulation of the isolated sciatic nerve, a compound action potential is produced. This represents

A summed electrical activity of all axons in the nerve

Explanation:

During the experiment with regards to the stimulation of the isolated sciatic nerve, a compound action potential is produced. It should be noted that this represents the summed electrical activity of all axons in the nerve.

Here, the summed electrical activity of all axons in the nerve represents the sum of the potentials that were recruited in the experiment.