Final answer:
C) The adrenal medulla is NOT a potential synapse location in pathway B of the sympathetic nervous system; it is a target organ for direct innervation by preganglionic sympathetic fibres.
Step-by-step explanation:
The location that is NOT a possible location for a synapse in pathway B of the sympathetic nervous system is C) The adrenal medulla. The sympathetic chain (A), spinal cord (B), and collateral ganglia (D) are all potential locations where synapses can occur. However, the adrenal medulla is not a synapse location; instead, it is a target organ that receives direct innervation from preganglionic sympathetic fibres without an intervening synapse. The sympathetic nervous system's pathways involve preganglionic neurons that originate in the spinal cord, which can synapse with ganglionic neurons at various locations. These locations include the sympathetic chain ganglia and collateral ganglia. Preganglionic sympathetic fibres that bypass the sympathetic chain can extend through splanchnic nerves to either collateral ganglia or directly to the adrenal medulla, where they release their neurotransmitters directly into the bloodstream, not at a synapse.