1. List the cellular structures over which an action potential travels, starting at the dendrites and traveling to where neurotransmitter molecules are released.

A neuron or a nerve cell is a unique cell, which performs an essential function of transmitting the nerve impulse in the form of action potential from one nerve cell to another. The point of communication between two neurons is known as a synaptic junction from where the transmission of a signal between presynaptic axon end and the postsynaptic dendrite occurs.  

The synapse present in the dendrite receives a signal in the form of neurotransmitter from the presynaptic axon. This results in the formation of an action potential that gets transmitted towards the cell body of a neuron. From the cell body, the conduction of impulse takes place via a long tubule composition known as an axon, which constitutes the nodes of Ranvier and reaches the nerve endings or the axon terminals.  

In the terminals, the change in potential results in the opening of the ions channels that discharge neurotransmitters in the form of acetylcholine, which further combines with the ligand-receptor situated on the next dendrite and thus repeats the process. Thus, the action potential travels from the dendrite to the cell body, and from there it travels to the terminals of the axon and eventually towards the ion channels and the ligand-receptor.  

the correct option is option d