The phylum with endoderm, mesoderm, and ectoderm is
a. cnidaria.
b. porifera.
c. platyhelminthes.
d. all of the above.

i believe it's c. the trait for large beaks will be passed on to future generations through natural selection.

since eventually smaller beaks would have to find another source of food or even eventually just die out from the lack of food.

answer increasing the intensity, duration,and frequency of exercise progressively;