Directional selection can be distinguished from disruptive selection by .the elimination of extreme variations of traitsb. selection for two extreme variations of a traitc. the preservation of gene frequenciesd. selection for one extreme variation of a trait  i know the correct answer isn't a 

The correct answer is option d, that is, selection for one extreme variation of a trait.  

Directional selection, in population genetics, refers to a medium of natural selection in which an extreme phenotype is preferred over other phenotypes, leading to the shifting of the frequency of an allele in the direction of that phenotype with time.  

On the other hand, disruptive selection illustrates the modifications in population genetics in which the extreme values for a trait are preferred over the intermediate values.  

The answer is option D.

Explanation:

Directional choice, in populace hereditary qualities, alludes to a medium of normal choice in which an extraordinary phenotype is favored over different phenotype, prompting the moving of the recurrence of an allele toward that phenotype with time.  Then again, troublesome determination delineates the alterations in populace hereditary qualities in which the extraordinary qualities for a characteristic are favored over the middle of the road esteems.

sorry, but you do not have posted the diagram.

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called