This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: Pathology
Carbohydrate tumor marker for breast cancer: 
Select and explain. 
A. CA 15-3, B. CA 125, C. CA 34, D. CA 19-9
A: CA 15-3
Answer: A: CA 15-3 
Explanation: Carbohydrate-rich tumor markers are specific antigens found either on the surface of tumor cells or may also be secreted as products by the tumor cells. CA: carbohydrate antigen/cancer antigen. Specific Proteins Immunoglobulins Multiple myeloma and other gammopathies Prostate-specific antigen and prostate-specific membrane antigen Prostate cancer Mucins and Other Glycoproteins CA-125 Ovarian cancer CA-19-9 Colon cancer, pancreatic cancer CA-15-3 Breast cancer CA 125: tumor marker of primary ovarian cancer of surface epithelial subtype.