Final answer:
A nurse with concerns about a medication dose should withhold administration, notify the nurse manager, and seek clarification to ensure patient safety.
Step-by-step explanation:
The nurse should not administer a medication dose that seems inappropriate, even if it is prescribed by the primary healthcare provider. If the nurse has concerns about the safety or appropriateness of the dose, especially if it is twice the usual adult dosage, the nurse has a professional responsibility to clarify and validate the prescription before administration. This is a safeguard to prevent medication errors and ensure patient safety. In the case of severe preeclampsia treatment with magnesium sulfate, any error in dosage could have serious consequences. Therefore, the correct response would be option (b) withhold the dose and notify the nurse manager who can facilitate further discussion between the nurse and the healthcare provider or involve other members of the healthcare team if necessary to resolve the concern.