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: Unknown
Pitting of nails can be seen in - 
Select and explain. 
A. Tinea unguium, B. Alopecia areata, C. Androgenetic alopecia, D. Peripheral vascular disease
B: Alopecia areata
Answer: B: Alopecia areata 
Explanation: Ans-B