A \(\overset{+}{−−−−→}\) Population density \(\overset{-}{←−−−−}\)B. If A increases population density and B decreases it then choose the correct option of A and B.

Both (b) and (c).

a-A can be mortality which brings positive change in population density

b-B can be emigration which brings negative change in population density

c-Values of A and B can never be equal

d-Both (b) and (c)

Both options (b) and (c) are correct.

In option (b), Emigration refers to the movement of individuals out of a population or habitat. When individuals leave a population, it leads to a decrease in population density. Therefore, if B represents emigration, it would be responsible for decreasing population density. Emigration refers to the movement of individuals out of a population, resulting in a decrease in population density.

In option (c), it is stated that the values of A and B can never be equal. This is true because natality (birth rate) and mortality (death rate) or immigration and emigration are independent processes with different factors influencing them. It is unlikely for these processes to be exactly equal at a given place and time, leading to unequal values of A and B.

Therefore, option (d) is the correct choice as it acknowledges that A can represent natality and/or immigration, bringing a positive change in population density, and B can represent mortality and/or emigration, bringing a negative change in population density. Additionally, it states that the values of A and B can never be equal due to the inherent differences between these processes.