What do you think might have been causing the slight sore throat you felt after visiting your sister's school? make sure to use "antigen a" and "antigen b" in your response?

I think the cause of the slight sore throat felt after visiting sister's school is the germs(microbes) at the school and you got the opposite antigen A or B contacted to you so you became sick.  
Antigen are substances that are capable of stimulating an immune response, specifically activating lymphocytes, which are the body's infection-fighting white blood cells. Antigens may be foreign antigens or auto antigens.