Final answer:
The removal of neurotransmitters from the synaptic cleft happens through reuptake, enzymatic degradation, and diffusion.
Step-by-step explanation:
The removal of neurotransmitters (NT) from the synaptic cleft can occur through various mechanisms. One way is through reuptake, where the neurotransmitter is pumped back into the presynaptic neuron from which it was released. This process clears the synapse and helps in regulating neurotransmitter production. Another method is enzymatic degradation, where enzymes in the synaptic cleft break the neurotransmitter down into inactive fragments. Additionally, neurotransmitters can simply diffuse away from the synaptic cleft.
Considering the options provided in the question, the correct answer is: a) Reuptake, enzymatic degradation, diffusion.