The correct answer of the given question above is option A. The line of defense that his immune system is exhibiting in this situation is the first line of defense. The first line of defense includes the physical or external line of defense of the body that are responsible for inhibiting of the entry of foreign microorganisms. Such include the skin, tears, cilia, mucus, urine flow and even stomach acid.
The correct answer is option A- HIV virus.
HIV virus is an example of enveloped virus, that has the ability to infect a host cell by attaching itself to it and fusing with the host cell. Once infected, the virus leaves the host cell and moves to another cells to infect them. The HIV virus contains glycoprotein spikes to attach to the host cell.
Answer:
Option A, The animal can only live in Australia
Explanation:
At present the Koala are found in several states of Australia such as
a) Queensland
b) NSW
c) Victoria
d) South Australia
Though the Koala is found on the eucalyptus trees of the temperate rain forest , they are only found in Australian geographies . There are several other place on planet earth where there is rainforest with eucalyptus trees and temperate climate, even though the Koalas are limited to Australia.
Hence Option A is correct.
I believe B is the answer..