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
A 40 year old female patient complains of excessive bleeding. Patient gives a history of road traffic accident 5 hours ago and had a lacerated wound on lower back region. Blood grouping test reveals presence of antigen A and antigen H. Anti Rh D antibody and anti B antibody are also present. This patient can receive transfusion from a donor with blood group? 
Select and explain. 
A. A positive, B. O positive, C. B negative, D. Bombay blood group
D: Bombay blood group
Answer: D: Bombay blood group 
Explanation: → Apart from A< B and O, RBC of type O contains large amount of another antigen called H substance.
→ H substance is genetically different from ABO, but is a precursor of A and B antigens.
→ An O group individual who inherits A or B genes, but fails to inherit H gene from either parent is called Oh phenotype or Bombay blood group.