Which of the following is the most appropriate way to determine how closely related two groups are using an evolutionary tree? a. Counting the number of nodes between the groups of interest.
b. Counting the number of other groups between the groups of interest.
c. Looking at the first (earliest) common ancestor of the two groups.
d. Looking at the last (most recent) common ancestor of the two groups.

Option D.

Looking at the last (most recent) common ancestor of the two groups.

Explanation:

The pattern of branching in a phylogenetic tree show how species evolved from different common ancestors.

In the evolutionary tree , most recent anscetor is use to determine two groups that are closely related because of similar traits or genes that is expressed in the two groups and the recent ancestors.

The recent anscetors pass the traits to the related species which have similar traits and it indicates that they are descendants of the common anscetors lineage.