I believe the answer would be transmission.
Removal of introns and the splicing together of exons.
Introns are regions of the DNA code that do not code for amino acids; therefore, they need to be removed before the mRNA strand is translated. Exons are the parts of the strand that do code for proteins, so they need to be pieced together once the introns are removed.
I think the answer is B, the interpretation of specific events as threatening or challenging. According to Hans Selye stress is a body's nonspecific response to any demand made on it, physical arousal to events seen as threatening, and mental arousal to events seen as challenging. However, there are effective strategies to cope with stress which include a sense of humor, relaxation, social skills, and social support.
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.