Answer:
Coevolution is the term that refers to a change in one species that results from a change in another species that it interacts with.
A good vector to genetically altered respiratory cells might be A VIRUS THAT HAS BEEN GENETICALLY ALTERED TO CARRY NORMAL HUMAN DNA.
Gene therapy is a medical method of treatment which uses genes to prevent or treat diseases. The method is used to correct the defects in genes which is causing a disease. In order to insert a normal gene to replace the defective one, a vector, which will carry the gene is needed. The vector that is usually used in this case is a virus, which has been doctored to carry a normal human DNA.
Since you say ‘which’ , in order to answer you, we would need the options you are given, but my answer would be
1. Not reusable
2. Might use up someday
3. Burning it will produce carbon dioxide and worsen global warming
Hope these can help :)