The equation total # of people in an area/(land) area in km2(or mi2) is used to calculate

a.
growth rate
b.
population density
c.
death rate
d.
carrying capacity

b)  population density

Explanation:

Population Density is the number of people living per unit of area.

Growth rate is the percentage change of population in the given time period.

Death rate or mortality rate is the measure of the number of deaths in  a particular population per unit time.

Carrying capacity is the number of people that a region can support without any environmental degradation.

explanation: magnetic pole, region at each end of a magnet where the external magnetic field is strongest. the south-seeking pole, or any pole similar to it, is called a south magnetic pole. unlike poles of different magnets attract each other; like poles repel each other.