A 32-year-old nulliparous female with a history significant for SLE and two miscarriages presents with localized tenderness of gradual onset, with erythema, along the path of a superficial vein in her foot. Although the symptoms are indicative of superficial thrombophlebitis, her PT is within normal limits and her PTT is prolonged. An antiphospholipid antibody syndrome is suspected, and she is treated empirically with indomethacin while a mixing test is ordered. Which of the following reactions in the coagulation cascade occurs through cofactors bound to phospholipids?
- Factor VII → Factor VIIa
- Factor IX → Factor IXa
- Factor X → Factor Xa
- Prothrombin (II) → Thrombin (IIa)
- All of the above