What does the trunk of the classic phylogenetic tree represent?
single common ancestor
pool of ancestral organisms
new species
old species

the tricuspid valve is present between right atrium and right ventricle

d. groundwater flows through the subsoil and deposits minerals.

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.