Final answer:
The infant would receive 1386 mg of medication in one week.
Step-by-step explanation:
To find how much medication the infant would receive in one week, we need to calculate the total dosage based on the infant's weight and the dosage rate. The dosage of medication is 11 mg/kg/day, and the infant weighs 18 kg. So, the daily medication dosage is 11 mg/kg/day x 18 kg = 198 mg/day.
Since the question asks for the medication the infant would receive in one week, we need to multiply the daily dosage by 7 (number of days in a week). So, the medication the infant would receive in one week is 198 mg/day x 7 days = 1386 mg.
Therefore, the correct answer is option 3) 1386.