In a certain bird species, clutch size (the number of eggs laid by a female in one breeding season) ranges from four to eight and the most frequent clutch size is six. this phenomenon is an example of:

The correct answer is- Stabilizing selection

Explanation:

In stabilizing selection nature favor the average value over the extreme value in a population. Therefore in stabilizing selection non-extreme traits are selected by nature. Stabilization selection can be seen in human birth weight, number of eggs laid by birds, etc.

Here the extreme value of trait is 4 and 8 but the most frequent clutch size is 6 therefore average is selected here over the extreme values which show that stabilizing selection is favored here. Therefore the phenomenon is an example of stabilizing selection.

the correct option is option d