Final answer:
Increased time spent searching for food at longer distances is the optimal behavior for an organism using central place foraging.
Step-by-step explanation:
The optimal behavior for an organism using central place foraging is increased time spent searching for food at longer distances (c).
This behavior allows the organism to maximize its energy gain by finding and exploiting food resources that are farther away from its central location.
For example, a bird that nests in a central location may spend more time flying to distant foraging sites to find abundant food sources.