Answer:
B: Population
Explanation:
Population is the number of people (well species) living in the same area at the same time.
Geological change will not cause a mass extinction, because it happens on a too big scale - on the scale of millions of years. During such long time, it is more likely that other causes will influence the survival of extinction of species, such as climate change or environmental disasters, and even if there is a small influence, it would not be significant next to other causes.
Answer: C). A tsunami would decrease abundance by causing physical damage to the organisms and their ecosystems.
An intertidal zone is also known as littoral zone. It is the region which is covers the foreshore and seabed. This region is exposed to the affects of tides. This region is highly vulnerable to tsunamis. The tsunami will disturb the habitat of organisms living in intertidal zone. Therefore, will result in decrease in abundance of aquatic organisms.
A fetus is especially at risk because they are under developed and easily susceptible to sicknesses or radiation
C.All living things are made of the same elements