Final answer:
The process of rearranging connections at synapses in the brain is known as synaptic plasticity, a critical component of learning and memory, making the correct answer C. plasticity.
Step-by-step explanation:
The rearrangement of connections at synapses in the brain is referred to as synaptic plasticity. This phenomenon facilitates the brain's ability to change throughout life. Synaptic plasticity is crucial to our nervous system's capacity to function, serving as the foundation for learning and memory. Specific processes such as long-term potentiation (LTP) and long-term depression (LTD) are important forms of synaptic plasticity that take place in the hippocampus, which plays a vital role in the storage of memories. Therefore, the correct answer to the student's question is C. plasticity.