Final answer:
The nurse should validate the client's concerns and offer reassurance that breast reconstruction is an option that can be discussed.
Step-by-step explanation:
The best response by the nurse in this situation would be option C. The nurse should validate the client's concerns and offer reassurance that breast reconstruction is an option that can be discussed. This response acknowledges the client's worries and provides a potential solution to address the issue of feeling sexually attractive after the mastectomy.