Answer:
A
Explanation:
a - What happens when organisms don't decompose? If there were no decomposers, wastes and the remains of dead organisms would pile up and the nutrients within the waste and dead organisms would not be released back into the ecosystem. Producers would not have enough nutrients.
b - What happens when a catastrophic mass extinction occurs? A mass extinction event is when species vanish much faster than they are replaced. This is usually defined as about 75% of the world's species being lost in a 'short' amount of geological time - less than 2.8 million years
c - What does the shifting of tectonic plates cause? At the “seams” where tectonic plates come in contact, the crustal rocks may grind violently against each other, causing earthquakes and volcano eruptions. The relatively fast movement of the tectonic plates under California explains the frequent earthquakes that occur there.
d - Volcanic ash doesn't actually do that.
Now, how do fossil fuels form? After millions of years underground, the compounds that make up plankton and plants turn into fossil fuels. Fossil fuels are formed when the organic matter that has been buried deep within the earth is subject to heat and pressure over millions of years. In both cases, heat and pressure are critical to the formation of fossil fuels.
so your answer is a
hope this helps:)
