4. Which blood type is the universal donor? Ois the universal domor. 5. Describe what causes blood type incompatibility. List two symptoms of a person experiencing blood type incompatibility. 6. Is it acceptable to transfuse O+ blood into a patient who has A-blood? Explain why or why not. 7. Is it acceptable to transfuse AB - blood into a patient who has A+ blood? Explain why or why not..