Final answer:
The nurse should explain to the client that the medication dutasteride can harm a developing fetus and therefore blood donation is usually deferred to prevent this potential harm.
Step-by-step explanation:
The nurse's best response to the client would be c) 'This medication can harm a developing fetus so your blood could be harmful if given to a pregnant woman.'
Dutasteride (Avodart) is a medication used to treat benign prostatic hypertrophy (BPH). It works by reducing the size of the prostate gland. However, it can also have potential risks to a developing fetus if the medication is passed through blood donation and given to a pregnant woman.
Therefore, individuals taking dutasteride are usually deferred from blood donation to prevent any potential harm to pregnant women.