What are the sources of aeroallergens responsible for allergic respiratory diseases?

Pollen from trees, grasses, and weeds are the main sources of aeroallergens responsible for allergic respiratory diseases.
Animal products, including mammals and arthropods, are not important sources of aeroallergens.
Algae is a relatively frequent aeroallergen.
a) Only statement I is correct.
b) Statements I and III are correct.
c) Statements I and II are correct.