Fossils are the preserved remains of organisms that has once lived. They are made up preserved remain of their body parts or activities as the case may be.
Dinosaurs are a group of large sized carnivores and herbivores that lived during the mesozoic.
Remains of their body parts have been found rock layers.
The Sahara desert in some part of Niger in Africa has provided good fossils of dinosaurs for paleontological studies.
The imprints of some the activities of these organisms have also been found.
Fossils are very good sources to show the existence of ancient lives.
The answer would be C. studying chromosomal changes in mitosis cell division. because mitosis is when the parent cells are just copies of an identical cell or known as the daughter cell.