A nurse's inadvertent medication error results in a severe allergic reaction and prolongs the client's hospitalization. The client could rightfully sue the nurse for which of the following?

A. Battery: Battery involves intentionally causing harmful or offensive physical contact without consent. In this scenario, the nurse’s action was unintentional, so battery does not apply. B. Assault: Assault refers to intentionally causing a client to fear imminent harmful or offensive contact. Since the medication error was accidental and not intended to threaten the client, this does not apply. C. Malpractice: Malpractice occurs when a professional fails to provide care consistent with the standards of practice, resulting in harm to the client. A medication error that causes a severe allergic reaction and prolongs hospitalization constitutes professional negligence, making malpractice the correct legal basis for a lawsuit. D. Abuse: Abuse involves intentional infliction of physical, emotional, or sexual harm. An inadvertent medication error causing harm does not meet the criteria for abuse, as there was no intent to harm the client.