It is not D. 165 ( i know this is wrong but it wont let me submit without an explanation as to why it's wrong.)
Carcinogens are found within cigerattes. Carcinogen refers to any subctance or agent that tends to produce a cancer.
A. It makes it easier to label the medication for the patient.
Pharmacy technicians should be able to calculate the duration of a prescription so that labelling of the medication for the patient is easy. Patient needs to take correct dosage and also up to the required number of days or months. If the pharmacy technicians are experienced enough then they have enough idea about the dosage and the time period of the medicines.