Pollen grains cause allergy to many people. The allergy-causing substance(allergen) of the pollen grain is present in______

The correct option is A

Exine

Pollen grains cause allergy to many people, especially in winter season, when the weather is dry and more pollen grains are present in the air. Sometimes this allergy can be severe. The allergy-causing substance (allergen) of the pollen grains is the sporopollenin, a highly resistance organic material. It is present in the outer wall of the pollen grain i.e. exine.