<span>Random fertilization adds to the genetic variation thanks to B)Fusion of sperm and ovum, each having a unique combination of chromosomes, introduces further variation. Fertilization is a process of fusion of sperm and ovum. In a random fertilization, it is expected that sperm and ovum each have a unique combination of chromosomes. Thus, the created zygote will have a unique combination of chromosomes which introduces variation.</span>
The answer would be: <u>Molten material that cooled quickly.</u>
Igneous rocks are formed by the cooling of molten material. So we can cross out the last two choices. The rock has no identifiable crystals so it is most likely an Extrusive igneous rock. They form on the surface where they cool quickly.
Those that form underground are called intrusive rocks. They cool slowly allowing enough time for crystal formation.
Humans even though i dont believe in evolution but that is the scientific answer
All of these are necessary, but what you need the most I would say is
D. Movement
Without movement, your body can stiff up, causing muscle problems which can lead to many various things.