Which of the following is NOT an example of a contagious disease?

The correct choice indicates that allergies are not a contagious disease. Allergies are immune system responses to substances that the body mistakenly identifies as harmful, known as allergens. These can include pollen, dust mites, certain foods, and pet dander, among others. Unlike contagious diseases, which can be transmitted from one person to another through direct contact, airborne particles, or shared surfaces, allergies cannot be spread between individuals. Each person's allergic reactions stem from their own unique sensitivities, and they do not stem from infectious agents, hence they do not exhibit the characteristics of contagious diseases.

In contrast, scabies, herpes, and tinea corporis are all caused by infectious agents and can be transmitted from one individual to another. Scabies is caused by a mite that burrows into the skin, leading to a highly contagious condition. Herpes is caused by the herpes simplex virus, which is spread through direct skin-to-skin contact or bodily fluids. Tinea corporis, commonly known as ringworm, is a fungal infection that can be contracted through direct contact with infected skin or contaminated surfaces. These properties distinguish them clearly from allergies, making it evident why allergies are not classified as contagious.