The correct answer is - A. A few centimeters a year.
Earth's crustal plates move very slowly, between 2 cm and 5 cm (depending on the plate) annually. This is the reason why it takes millions of years for them to significantly change their position, and with it the appearance of our planet. These crustal plates are slowly moving around the planet because they are powered by flow in the interior mantle.
The electrochemical impulse is composed of an action potential travelling from the dendrite to the cell body to the axon of the neuron. The main neurotransmitter is acetylcholine which is released at either the synapse or the neuromuscular junction.
