Coaches will often urge athletes to exercise when they have a cold or other infection. what is the immunological reasoning behind this sage advice?

Exercise is the primary advice the coaches give to the athletes if they get a cold or any other infection. The main reason behind this advice is the fact that exercising strengthens the immunity of a person. When a person has an infection, the strengthening of the immune system will help his body to efficiently fight against the infectious pathogens. The blood circulation is increased which is involved in the enhancement of the acute immunity of the person.

i think the answer is a.keratin is the pigment responsible for skin color.