Final answer:
The correct-gauge needle for a Mantoux test is 25. The Mantoux test is a screening tool used to determine if a person has been exposed to tuberculosis.
Step-by-step explanation:
The correct-gauge needle for a Mantoux test is 25. The Mantoux test is a screening tool used to determine if a person has been exposed to tuberculosis. A positive result is indicated by redness, swelling, or hardness at the site of the injection, and the size of the response is measured to determine the final result. The gauge of the needle refers to its size, and a gauge of 25 is most commonly used for the Mantoux test.