I would go with A : weathering and erosion
I was going to say C : volcanoes and earthquakes but when you read the pictures it says “ Mountains , low hills & rolling plains “
Hihi!
The answer would be 2) Plenty of food! If you have plenty of food then the likely hood for more of the population to live would increase, the rest of the causes would cause decrease in the population!
I hope I helped!
-Jailbaitasmr
A. The conditions under which the organism died and how it was buried.
Reason for Answer: This is because fossils are used to determine the relative age of sedimentary rocks and are used to provide information on past climates, environments, and many more.