In the extrinsic pathway, factor III and factor VII form an enzyme complex. Which factor does it activate?

1. Damaged extravascular cells release factor III, tissue thromboplastin, on contact with plasma. 2. Calcium ion and then factor VII, proconvertin, are added, and factor III activates factor VII. 3. The resulting enzyme complex activates factor X, the Stuart-Prower factor. 4. Activated factor X is the entry point to the common pathway. 5. Factor VII is already part of the complex, so it cannot be what the complex activates. 6. Factors XII and XI belong to the intrinsic pathway and never appear in the extrinsic sequence. 7. The whole extrinsic sequence completes in a matter of seconds, which is why it is called the quicker and more direct route. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.5 Hemostasis_