Many Species of Field Mice Are Able to Reproduce Several

Multiple Choice

Many species of field mice are able to reproduce several times a year and produce litters with multiple offspring. However, an ecologist noted that the population size of mice, as measured in a California grassland, did not change from year to year. The factors that keep natural populations from increasing are collectively called

A) nonliving factors.
B) exponential growth.
C) scramble competition.
D) biotic potential.
E) environmental resistance.