Which type of antibody is produced in response to allergens?

Allergy is due to the release of chemicals like $...$ and $...$ from the $...$ cells.

Assertion: Many visitors to the hills suffer from skin and respiratory allergy problems.
Reason: Conifer trees produce a large quantity of wind-borne pollen grains.

Hypersensitivity to an allergen is associated with ................

In allergy and urticaria,the local arterioles dilate due to an increased substance released from mast cells,called:

Which of the following is caused by an allergy?