A nurse is reviewing the medical record of a client who is requesting combination oral contraceptives. Which of the following conditions in the client's history is a contraindication to the use of combination oral contraceptives?

A. Hyperthyroidism: Hyperthyroidism is not an absolute contraindication to combination oral contraceptive (COC) use. While thyroid hormone levels should be monitored, estrogen-containing contraceptives generally do not exacerbate hyperthyroidism in otherwise stable clients. B. Thrombophlebitis: A history of thrombophlebitis or thromboembolic disorders is a significant contraindication to COC use. Estrogen in COCs increases coagulation factors and the risk of venous thromboembolism, making use in clients with prior thrombotic events unsafe. C. Diverticulosis: Diverticulosis does not increase the risk of complications from COCs, nor do COCs exacerbate this gastrointestinal condition. It is not considered a contraindication. D. Hypocalcemia: Low serum calcium levels are unrelated to COC use. COCs do not significantly affect calcium metabolism, so hypocalcemia is not a contraindication to their use.