The correct answer is c: represents the divergence of two or more groups from a common ancestor.
A cladogram is a diagram that shows the relationships among various biological species based on similarities and differences in their physical or genetic characteristics. Each branching point, known as a node, signifies where a single lineage diverges into two or more lineages, indicating that those groups share a common ancestor. This is crucial for understanding evolutionary relationships and constructing phylogenies.
Options like ‘a: is called a root’ are misleading because the root is usually the base of the cladogram. ‘b: represents a clade’ refers to a group of organisms that includes an ancestor and all its descendants, which is different from what branching points indicate. ‘d: represents horizontal gene transfer’ and ‘e: marks the divergence of two kingdoms’ are also incorrect, as they do not specifically describe the function of branching points in cladograms.