**Core Concept**
The use of oral contraceptive (OC) pills is a common method of birth control in women of childbearing age. However, certain conditions or situations contraindicate the use of OC pills due to increased risk of adverse effects or thromboembolic events.

**Why the Correct Answer is Right**
The primary contraindication of OC pills is the presence of a thromboembolic disorder, such as deep vein thrombosis (DVT) or pulmonary embolism (PE). The estrogen component of OC pills increases the risk of blood clot formation, which can lead to serious complications. Women with a history of DVT or PE should avoid using OC pills as they may increase the risk of recurrent thromboembolic events.

**Why Each Wrong Option is Incorrect**
**Option A:** **Migraine with aura** is a relative contraindication of OC pills, but not an absolute contraindication. Women with migraine with aura may be at increased risk of stroke, but the risk can be managed with careful selection of OC pills and monitoring.

**Option B:** **Hypertension** is not a contraindication of OC pills. In fact, some studies suggest that OC pills may have a beneficial effect on blood pressure in women with hypertension. However, women with uncontrolled hypertension or other cardiovascular risk factors should be cautious when using OC pills.

**Option C:** **Breast cancer** is a relative contraindication of OC pills. Studies have shown that the use of OC pills may increase the risk of breast cancer, particularly in women who use them for more than 5 years. However, the risk is generally considered to be small.

**Option D:** **Diabetes** is not a contraindication of OC pills. In fact, some studies suggest that OC pills may have a beneficial effect on glucose metabolism in women with diabetes. However, women with diabetes should be cautious when using OC pills, particularly if they have other cardiovascular risk factors.

**Clinical Pearl / High-Yield Fact**
Women with a history of DVT or PE should avoid using OC pills as they may increase the risk of recurrent thromboembolic events. However, the risk can be managed with careful selection of OC pills and monitoring.

**Correct Answer: D. Diabetes is not a contraindication of OC pills.**