Final answer:
Dr. Elmer's belief aligns with the restorative theory of sleep, which suggests that sleep is used for biological restoration, including replenishing lost chemicals.
Step-by-step explanation:
Dr. Elmer's belief that sleep is needed to replenish the body's natural chemicals lost during daily activity relates most closely to the restorative theory of sleep. This theory posits that sleep is necessary for the restoration and recovery of the body and brain from the daily energetic demands.
The restorative theory of sleep suggests that the body uses sleep to repair and rejuvenate itself, including the replenishment of neurotransmitter levels, the clearing of metabolic waste from the central nervous system, and the repair of cellular damage. This theory closely aligns with the understanding of sleep's adaptive function, which accounts for the evolutionary necessity of sleep for biological restoration.