A species of malaria-carrying mosquito lives in a forest in which two species of monkeys, A and B, coexist. Species A is immune to malaria but species B is not. The malaria-carrying mosquito is the chief food for a particular kind of bird in the forest. If all of these birds are eliminated suddenly by hunters, which of the following would be the immediate observable consequence? (A) Increased mortality in monkey species A (B) Increased mortality in monkey species B (C) Increased mortality in the malaria-carrying mosquitoes (D) Emergence of malaria-resistant strains in monkey species B (E) Emergence of malaria-sensitive strains in monkey species A

Immunization is used by which the individual immune system are fortified against the particular pathogen. Immunization protects the organism from the specific disease.

Two species of monkey A and B, the species A has been immunized while B is not. The birds are eliminated by hunters and lack of immunization in species B causes the increased mortality rate of the monkey of species B.

Thus, the correct answer is option (B).