Why are molecular clocks important in the construction of cladograms?

The correct answer would be because the molecular clock helps in finding the time a species took to divergent and evolved by comparing mutation in the species occurs.

The molecular clock is a way to quantify the relatedness in two close species diverges from an ancestor species that help in constructing the cladogram. A cladogram is a phylogeny tree based on molecular clock or mutation on DNA level.