Answer: a trillion cells
Explanation:
Cells are the basic building blocks of living things. The human body is composed of trillions of cells, all with their own specialised function. Cells are the basic structures of all living organisms
The correct answer is - A. Death rate.
We get the fertility rate from the birth rate and the death rate. More specifically, from the number of the children that are born in a given time frame (usually a year) we minus the number of the people that have died in the same time frame, so the difference between them gives us the fertility rate.
The fertility rate can be positive (in the difference is a positive number) and negative (if the difference is negative number).