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: Dental
"Corn-Cob" appearance seen in 
Select and explain. 
A. Supragingival calculus, B. Subgingival calculus, C. Supragingival plaque, D. Subgingival plaque
C: Supragingival plaque
Answer: C: Supragingival plaque 
Explanation: None