Final answer:
Parents of a child prescribed an anthracycline drug should watch for signs of cardiotoxicity, a severe and potentially irreversible side effect of this chemotherapy agent. Therefore, the correct option is d.
Step-by-step explanation:
If a child is prescribed an anthracycline drug, the nurse would teach the parents to observe for signs and symptoms of cardiotoxicity. Anthracyclines, like Doxorubicin, Daunorubicin, and Idarubicin, are potent antitumor drugs that can intercalate with DNA and inhibit topoisomerase II, leading to DNA strand breakage. Unfortunately, these drugs also have severe side effects including cardiotoxicity, which can manifest as impaired heart function, one of the risks associated with this class of chemotherapy agents. Parents should be alert for symptoms of heart issues in their child, as these effects can be severe and sometimes irreversible.