Gap junctions are relatively rare and are found in the
Cardiac muscles,
Smooth muscles of the intestine
Smooth muscles of epithelial cells of the lens.
All of the above
At electrical synapses, there is continuity between the presynaptic and postsynaptic membranes of the neurons. This continuity is due to the gap junctions. Hence, there is a minimal synaptic delay due to direct flow of ions from one neuron to another through gap junctions. These are relatively rare and are found in the cardiac muscles, smooth muscles of the intestine and epithelial cells of the lens. Hence, the correct answer is option a.