DNA contains equal amounts of adenine/thymine and guanine/cytosine.
If an invasive species is added into a food chain/web, it becomes overpopulated/a pest because it has no natural predators.
It can also disrupt the food chain/web by eating the food supplies of the native organism leading to competitions.
If a person comes in contact with this same virus years later, our body produces antibodies to get rid of or kill the virus
Explanation:
When a person is infected by a virus, the infected person's body develops antibodies as an immune response to act against the virus. Antibodies are produced as part of humoral immunity.
Antibodies work by neutralizing the viral activity, agglutination, phagocytosis or by complement system.
Antibodies are protein compounds which can recognize the invading pathogens and attack them.
Antigens or viral proteins in the virus leads to the production of antibodies in the host's body.
The specific antibodies triggers innate immune response upon detecting specific viral antigens when infected and will help the body to get rid of or kill the virus.
American prairie, bison and badgers don't live in any of the other options naturally.