Which is the most appropriate nursing action related to the administration of digoxin (Lanoxin) to an infant?

A. Checking respiratory rate and blood pressure before each dose: While respiratory status and BP are important, apical heart rate is the most critical parameter to assess due to the drug's potential for causing bradycardia. B. Counting the apical rate for 30 seconds before administering the medication: The apical heart rate should be counted for a full 1 minute in infants, not 30 seconds. C. Withholding a dose if the apical heart rate is less than 100 beats/minute: Digoxin should be held if the apical HR is <100 bpm in infants, due to risk of bradycardia and cardiac arrest. D. Repeating a dose if the child vomits within 30 minutes of the previous dose: A repeat dose is not recommended without physician consultation, as vomiting may be a sign of toxicity.