For a Peripheral Nerve Bridge to Be Successful, Which of the Following

For a peripheral nerve bridge to be successful, which of the following must occur?

A) The environment into which the axon is growing must be permissive.
B) The neuron whose axon is extending must be of the same type as those occupying the environment in which they will grow.
C) The growing axon has a limit of only 2 mm.
D) The growing axons must be capable of both anterograde and retrograde transport of proteins.
E) The peripheral nerve bridge must come from the same animal into which a transplant is to be made; i.e., an auto-transplant.