The correct answer to this question is option 2 - Ringworm. Ringworm is a skin infection caused by a fungus. Despite the name, ringworm is not caused by a worm, but rather by a group of fungi called dermatophytes. These fungi can infect the skin, scalp, or nails and cause symptoms such as red, itchy, circular rashes. The infection can be transmitted through direct contact with an infected person or animal, or by coming into contact with contaminated objects or surfaces. It is important to note that ringworm is a treatable condition and can usually be cured with antifungal medications. This distinguishes it from other options listed in the question, such as roundworm (a type of parasitic worm), tapeworm (another type of parasitic worm), and filaria (a parasitic worm that causes filariasis).