a. What are most respiratory infections in children caused by?

(A) Bacteria
(B) Viruses
(C) Fungi
(D) Allergens
b. Why do some children have more respiratory problems than others?

(A) Genetic factors
(B) Environmental factors
(C) Immunological factors
(D) Lifestyle factors
c. What are some examples? Explain your responses.

(A) Asthma
(B) Bronchitis
(C) Pneumonia
(D) All of the above