A biologist studied the population of rats in a barn, He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is :

A biologist studied the population of rats in a barn, He found that th

1.	A biologist studied the population of rats in a barn, He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is :
A.	10
B.	15
C.	5
D.	zero
Answer» E.