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
Pitting nail dystrophy seen in – a) Dermatophytic infectionb) Psoriasisc) Lichen planusd) Seborrheic dermatitis 
Select and explain. 
A. a, B. c, C. ac, D. bc
D: bc
Answer: D: bc 
Explanation: Skin disorders causing nail pitting → Psoriasis, Alopecia areata, Reiter's syndrome, Lichen planus,Eczema, Incontinetia pigmenti