A young adult female client who is planning to become pregnant asks the nurse if she can continue taking isotretinoin for cystic acne. Which information is most important for the nurse to provide this client?

A. While breastfeeding is not recommended during isotretinoin therapy, the most pressing concern for pregnancy is to discontinue the medication before conception. B. Isotretinoin can be harmful if excessive vitamin A is taken, but the critical issue is to stop the medication before pregnancy. C. Monitoring liver function is important during isotretinoin therapy but does not directly address the pregnancy-related risk. D. Isotretinoin is highly teratogenic, so it is crucial to discontinue the medication at least one month before attempting to conceive to avoid potential birth defects.