Chronic betel (areca) nut chewing characteristically causes reddish-brown staining of the mouth and is strongly associated with:

Correct answer: A. Oral submucous fibrosis (and elevated oral cancer risk)

• A. Correct. Betel/areca chewing stains the oral tissues and is a major cause of oral submucous fibrosis and increased oral squamous cell carcinoma risk.
• B. Geographic tongue is a benign migratory glossitis, unrelated to betel.
• C. Black hairy tongue relates to poor hygiene/antibiotics/tobacco, not specifically betel fibrosis.
• D. Median rhomboid glossitis is a candidal lesion of the tongue dorsum.