The Following Questions Refer to the Evolutionary Tree Shown Below

Multiple Choice

The following questions refer to the evolutionary tree shown below.
The horizontal axis of the cladogram depicted below is a timeline that extends from? 100 000 years ago to the present; the vertical axis represents nothing in particular. The labelled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since? 50 000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

-Which of the five common ancestors, labelled V-Z, has given rise to the greatest number of species, both extant and extinct?

A) V
B) W
C) Z
D) Both W and Z can be considered to have given rise to the greatest number of extant and extinct species.
E) Both X and Y can be considered to have given rise to the greatest number of extant and extinct species.