The question is B soil erosion upstream
Genetic variation is the answer to ur question
Answer: Option C.
Population density is the total number of organisms within a fixed area.
Explanation:
Population density is the total number of organisms per unit area. Population density is calculated by dividing the number of organisms by the unit area either in square kilometers, squaremeters, square miles.
Population density =number of organisms ÷ unit of land area.
The process is called osmosis..its the transportation of water
