You observed many sand hill cranes on your walk. Two sand hill cranes flapped their wings and hopped up and down when you walked on the path near where their bright orange baby stood. You observed a(n) .

This question lacks options, the options are:

A) symbiosis

B) ecosystem

C) community

D) population

E) biosphere

The answer is D) Population

Explanation:

Living organisms in an ecosystem are usually found in numbers living together in a given area. This is termed POPULATION in ecology. A population refers to the group of living organisms that belongs to the same species living together in the same habitat and have the ability to interbreed i.e. mate and reproduce with one another.

This is the case in this question where many sandhill cranes (large flying birds) were observed in a particular area, which represented their habitat. Asides the group of sandhill cranes living together, they were also observed to be interbreeding. This was evident in the observation of two sandhill cranes hopping up and down around their bright orange baby. This shows that members of the population are capable of mating and reproducing fertile offsprings.

This observation completes what a POPULATION is all about, hence, a population was observed.