Answer:
The correct answer is option c. "Tetracycline must be discontinued before beginning the isotretinoin".
Explanation:
Isotretinoin is a medication used to treat cases of severe acne, having dramatic positive effects since the patients start the treatment. However, the use isotretinoin should be monitored by a doctor because it is hard to process and could cause renal side effects. In this case, the patient must discontinue its treatment with tetracycline before start using isotretinoin.