Washington Barber License Practice Exam

A patch test is a method used to determine if there is an allergic reaction to a substance. If the test results in redness or inflammation at the site of application, it signifies that the person is allergic to the substance. This means that when their skin comes in contact with the substance, their immune system reacts by causing inflammation, which is a sign of sensitivity and not resistance or immunity. Peroxide can also cause skin irritation, but this is not a sign of an allergy. Resistance is the ability to fight against an infection or disease, and immunity is the ability to resist getting the infection or disease in the first place. Neither of these options are applicable in this situation. Therefore, option A is the correct answer.