A nurse is caring for a client who is 3 days postpartum and is attempting to breastfeed. Which of the following findings indicate mastitis?

A. "Swelling and redness in one breast, accompanied by flu-like symptoms." Mastitis is a bacterial infection in breastfeeding mothers, typically caused by Staphylococcus aureus. It presents with unilateral breast pain, erythema, swelling, fever, and flu-like symptoms. B. "A white patch on a nipple." A white patch on the nipple may indicate a blocked milk duct or thrush (Candida infection), not mastitis. C. "Symmetrical breast swelling with a sudden increase in milk production." Engorgement occurs when the breasts overfill with milk, leading to bilateral swelling, tenderness, and firmness, but no systemic signs of infection like fever or flu-like symptoms. D. "Bilateral breast tenderness and engorgement with no fever." Normal breast engorgement can cause discomfort, but mastitis typically affects one breast and causes fever and systemic symptoms.