This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Hairy tongue is characterized by 
Select and explain. 
A. Hypertrophy of fungiform papillae, B. Hypertrophy of foliate papillae, C. Hypertrophy of filiform papillae, D. Hypertrophy of circumvallate papillae.
C: Hypertrophy of filiform papillae
Answer: C: Hypertrophy of filiform papillae 
Explanation: None