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: Pathology
The most common site for carcinoma of the pancreas - 
Select and explain. 
A. Head, B. Ampulla, C. Body, D. Tail
A: Head
Answer: A: Head 
Explanation: Pancreatic carcinoma 

Pancreatic carcinoma is the most common malignant tumor of pancrease.

Risk factors

Smoking → Most consistent risk factor.   
Chronic pancreatitis     
Obesity
High fat, low fibre diet.
Diabetes

Pathology

Pancreatic carcinoma are ductal adenocarcinomas.
The most common site is head of pancreas. The distribution is as follows.

Head (70%)
Body (20%)
Tail (10%)