Answer:
A. The result will be an increase in available Serotonin in the synaptic cleft causing the post synaptic cell to increase the number of Serotonin receptors.
Step-by-step explanation:
When a serotonin reuptake pump is blocked, serotonin molecules that are released from the presynaptic neuron into the synaptic cleft are prevented from being reabsorbed back into the presynaptic neuron. This leads to an accumulation of serotonin molecules in the synaptic cleft, which increases the available serotonin. This increase in available serotonin will stimulate the post-synaptic neuron to increase the number of serotonin receptors, in order to maintain homeostasis. This allows for greater serotonin signaling and transmission across the synaptic cleft.