Which of the following statements is true regarding communication in neurons

Free electrons are moved along the plasma membrane of the axon and control the expression of neurotransmitters

A chemical signal travels along the axon and is converted into an electric impulse at the synapse

An electric impulse travels along the length of the axon. The electric impulse is converted to a chemical signal at the synapse.

An electrical signal is converted to a chemical signal by the myelin sheath before it reaches the synapse