The following options are attached to the question above:
A. When a new trait evolves
B. When an ancestor becomes extinct
C. When it is discovered
D. When it becomes large enough
ANSWER
The correct option is A.
A cladiogram refers to diagram that is used to show the relationships among organisms. The diagram make use of lines, which branch off in different directions and which end up at a clade. A clade refers to a group of living organisms that share a last common ancestor. The diagram is used by biologists to visualize group of organisms that are been compared in order to determine their relatedness and their most common ancestors. In cladiogram, a group of organism branch off when a new trait emerge.