It is b. A population with many phenotypes
You can infer that the birds once had a common ancestor but became separated. Mutations in copying their genes stacked and caused changes in the beaks so the birds could be more well off or better adapted in their new environment.
The best answer is B - Proteins.
Proteins make up enzymes, or to put it another way enzymes are made up of protein. It is enzymes that speed up the chemical reactions. Enzymes are organic catalysts, substances that speed up a (biochemical) reaction but do not take part in the reaction and remain unchanged at the end of the reaction.
In man, there are many enzymes. The majority of these are found in the digestive system where they greatly aid the process of food breakdown from complex molecules to simple molecules. Examples include salivary amylase found in saliva, which begins the gradual breaking down of starch into glucose right from the moment food is placed in the mouth and mixed with saliva. Pepsin in the stomach breaks down protein.
Phylogenetic trees show the evolutionary pathways and connections among organisms. A phylogenetic tree is a diagram used to reflect evolutionary relationships among organisms or groups of organisms.
