Aphylogenetic tree grouping that consists of a common ancestor and all of its descendants is known as a group.

An approach to systematics in which organisms are placed into groups called clades based primarily on common descent. A group of species that includes an ancestral species and all its descendants. Pertaining to a group of taxa that consists of a common ancestor and all of its descendants. It is equivalent to a clade.

The answer is c) tons

You should never redesign your experiment. try and see what in your experiment you made a mistake on or try and test your experimemt with somebody else. see if they get the right results.