Select the incorrect option for electrical synapses.

What is an electrical synapse?

The figure shows an axon terminal and synapse. Select the option giving correct identification of labels $A-D$.

Which of the following statements is correct regarding electrical synapses?
$I.$ Pre and postsynaptic membranes are in very close proximity at electrical synapses.
$II.$ Electric currents are involved in the transmission of impulses.
$III.$ Transmission of an impulse across electrical synapses is very similar to impulse conduction along a single axon.
$IV.$ Impulse transmission is always faster in electrical synapses than across chemical synapses.
$V.$ Electrical synapses are rare in our system.
The correct option is:

What is a neurotransmitter?

Synaptic vesicles are found in