The correct answer is option 1: subtracting the death rate from the birth rate.

Natural Population Change is a calculation that measures the change in population size over a specified period of time. It is calculated by subtracting the death rate from the birth rate.

Birth rate refers to the number of births in a population per 1,000 individuals per year. It essentially represents the rate at which new individuals are added to the population through birth. A higher birth rate suggests a faster population growth.

Death rate, on the other hand, refers to the number of deaths in a population per 1,000 individuals per year. It represents the rate at which individuals are lost from the population through death. A higher death rate indicates a higher mortality rate in the population.

By subtracting the death rate from the birth rate, we can determine the net change in population due to natural causes. A positive natural population change indicates that the birth rate exceeds the death rate, resulting in population growth. Conversely, a negative natural population change suggests that the death rate exceeds the birth rate, leading to population decline.

Therefore, option 1 is the correct answer as it accurately describes the calculation for determining natural population change.