Final answer:
A history of deep vein thrombosis may indicate that the patient is not a good candidate for oral contraceptives due to the increased risk of blood clots.
Step-by-step explanation:
A history of deep vein thrombosis may indicate that the patient is not a good candidate for oral contraceptives. Deep vein thrombosis is a blood clot that forms in a vein deep within the body, typically in the legs. Taking oral contraceptives can increase the risk of blood clots, so a patient with a history of deep vein thrombosis may be advised against taking these drugs to minimize their risk.