Background Paragraph: Hepatitis B is a contagious virus that affects the liver, infection can last from a few weeks to a serious lifelong illness. Two different types of infection exist for this disease, "acute" and "chronic." Acute Hepatitis B is a short term illness that occurs within 6 months of exposure, Chronic Hepatitis B is long term and happens when the virus remains in the body. The younger the child is, the greater their chance of developing a chronic infection and this risk goes down as the child gets older. Approximately 90% of infected infants will develop a chronic infection.[3]. 
Story: Bob has just graduated from medical school. He went on to serve his community. Especially he is interested in treating children. One day he saw two children, child M and child N, and found child M is infected with Acute Hepatitis B while child N is infected with Chronic Hepatitis B. Next day he saw two other children, child O and child P. Child O was younger, but child P was older.
Did child M had long term illness or short term illness? Did child M's illness occur within six months of exposure or the virus remained in his body? Did child N had long term illness or short term illness? Did child N's illness occur within six months of exposure or the virus remained in his body? In which child the virus remained in the body, child M or child N? Which child had less chance of developing a chronic infection, child O or child P? Which child had long term illness, child M or child N? Which child had more chance of developing a chronic infection, child O or child P? Which child had short term illness, child M or child N? Which child's illness occured within six months of  exposure to the virus, child M or child N?