Species of Oak Trees Periodically Have Years of Large Acorn

Multiple Choice

Species of oak trees periodically have years of large acorn production, followed by years of lower acorn amounts. In years of plenty, squirrel populations will experience an increase due to increased food availability of acorns. Then, squirrel populations will decrease after lower acorn abundance. This is an example of

A) a population cycle.
B) net primary productivity.
C) a renewable resource.
D) a density-independent factor.