Synapses are intersections where the axons of one neuron meet the dendrites of another neuron where neurons make direct contact with one another chemical structures that allow dendrites to send their messages to axons the area where neurons determine whether a stimulus exceeds the absolute threshold or not

The right answer is A. intersections ... another neuron.

The synapse refers to a functional contact zone that is established between two neurons, or between a neuron and another cell (muscle cells, sensory receptors ...). It ensures the conduction of an action potential in the presynaptic neuron into a signal in the postsynaptic cell. It is estimated that for some cell types (eg pyramidal cell, Purkinje cell ...), about 40% of the membrane surface is covered by synapses.