Aphthous ulcers are also known as which of the following?

• A. Cold sores
• B. Oral thrush
• C. Canker sores
• D. Xerostomia

Answer: (C)

Aphthous ulcers refer to canker sores—small, shallow, painful ulcers that appear on the inner mucous membranes of the mouth. They’re non-contagious and typically heal on their own within 1–2 weeks. This term best fits because it describes the common presentation of these mucosal lesions, unlike cold sores (caused by herpes simplex virus and usually on the lips), oral thrush (a white, scraped-off fungal infection), or xerostomia (dry mouth due to reduced saliva).