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: Surgery
Site of diabetic foot ulcera) Medial Malleolusb) Lateral malleolusc) Heeld) Head of metatarsale) Head of toes 
Select and explain. 
A. cd, B. bc, C. bd, D. ac
A: cd
Answer: A: cd 
Explanation: "Diabetic ulcers commonly result from decreased protective sensation. Diabetic ulcers are usually found on the plantar surface of the foot over the metatarsal heads or heel." - Sabiston.