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: Skin
Erythema nodosum is due to A/E: 
Select and explain. 
A. Contraceptive pilles, B. Barbiturates, C. Penicillin, D. Sulphonamides
B: Barbiturates
Answer: B: Barbiturates 
Explanation: B i.e. Barbiturates