Question

why is it important to know a person’s rhesus factor before a blood transfusion?
a patient who is rh+ can receive only rh– blood.
a patient who is rh– can receive only rh+ blood.
a patient who is rh+ can receive only rh+ blood.
a patient who is rh– can receive only rh– blood.

Explanation:

To determine the correct answer, we analyze Rh blood type compatibility:

• Rh+ patients can receive Rh+ or Rh- blood (so options A and C are wrong).
• Rh- patients lack Rh antigens. If they receive Rh+ blood, their immune system may produce antibodies against Rh antigens, causing a transfusion reaction. Thus, Rh- patients should only receive Rh- blood (option D is correct, option B is wrong).

Answer:

D. A patient who is Rh– can receive only Rh– blood.