Ms. R owns a home but lives with her sister. She lets her son live in the house. The mortgage only has Ms. R's name on the property as she did not add her son's name to the property deed. Since her son lives in the house, he makes the monthly mortgage payment. Who can deduct the mortgage interest expense for the year? A. The son, since he makes the payments. B. Ms. R, since she owns the property and is liable for the payments. C. Both, since they are related. D. Neither, since Ms. R is not paying her liability and her son is paying for what he is not liable.