Final answer:
A wheal is a round, raised skin lesion with itching that is a positive sign of reaction to allergic testing.The correct option is A.
Step-by-step explanation:
The correct answer is A. Wheal.
In allergic testing, a round, raised skin lesion with itching is known as a wheal. It is a positive sign of a reaction to the allergen being tested.
For example, in skin testing for allergies, if a person is allergic to a particular substance such as pollen, when that substance is injected into their skin, a wheal may appear at the injection site along with itching. This indicates that the person is having an allergic reaction to the pollen.