it will have to be B. Populations will decline since individuals will be less likely to successfully reproduce. because they will not be able to breed with other birds on the breeding grounds.
Answer:
The correct answer would be option B.
Due to the early arrival of springs, the warblers could not find ideal sites for nesting.
In addition, the early-spring food sources also get depleted by the time they reach breeding grounds.
Consequently, the reproduction and survival rates of the warblers would decrease.
Ultimately, the population size of the warblers would decrease.