Pharmacists must know their job. If they did not, someone could easily die. . . . Interviewers will give you couple of questions about your studies, and they can even ask some practical questions, to see whether you remember anything from your studies.
You should pick practical subjects and residency for your answer, since that will show that you like the real job of a pharmacist, and that you know what will be expected from you in the pharmacy or hospital.
They know your marks
Each of us dislike some subjects. Interviewers have most likely seen your marks and know what troubled you at school. Therefore you should tell them about your weaknesses, and about subjects you struggled with. Nobody is perfect. Interviewers themselves had their problems with certain subjects, and they will appreciate your honesty and humility in this case.
I really enjoyed the APPE we had to complete. I had the chance to do a real job under supervision, and the experience convinced me once again that to work as a pharmacist is what I want to do in my life. I believe it was a good preparation for the job. And mathematical subjects, especially Calculus, were the toughest. I needed a few attempts to pass the exam. I understood, however, that every subject is important, and I worked hard until I finally passed the exams.