Answer:
disruptive selection
Step-by-step explanation:
Disruptive selection is the natural selection that favors two extreme phenotypes but does not favor the intermediate phenotype. Here, the survival and reproductive success of two extreme phenotypes are higher than that of the intermediate phenotype due to their higher fitness value in the prevailing conditions. The presence of deeper voices in males and less deep voices in females due to high and low levels of testosterone respectively represents the disruptive selection as the phenotype present at two extreme ends are favored.