Which factor could contribute to an overall population decrease? a) decreased birth rate b) increased immigration c) decreased infant mortality d) decreased overall mortality

The correct answer is option A) decreased birth rate.

The decrease in the birth rate would lead to overall decrease in the population, as the number of new individuals added to the population would be less.

Reason for the incorrect options:

An increased in the immigration of individuals, would increase the overall of number of individuals in a particular area, so, it would lead to increase in population.

The decreased infant mortality or overall mortality would allow the survival of more individuals in a particular region, which would cause an increase in the population.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.