Answer:
Children younger than 5, but especially children younger than 2 years old. Adults 65 years of age and older. Pregnant women (and women up to two weeks postpartum)
Explanation:
I believe the correct answer would be <span>variation. The definition of variation in biology means,</span><span> any difference
between cells, individual organisms, or groups of organisms of any
species caused either by genetic differences or by the effect of environmental factors on the expression of the genetic potentials. So i think that organisms can also be classified as variation. Hope this helped. ♥ ☺
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Protozoans, bacteria, fungi... viruses are not organisms