How Often Should You Check to See If the Answers

How often should you check to see if the answers to dosage calculations are reasonable?

A) The first time you perform a calculation for an unfamiliar medication
B) The first time you calculate a recurring dosage for a patient
C) Every time you perform a calculation for an unfamiliar patient
D) Every time you perform a calculation for an unfamiliar medication
E) Every time you perform a dosage calculation