• Local Utero-Ovarian Countercurrent Transfer of $\text{PGF}_{2\alpha}$: In ruminants, the extensive physical intertwining and adherence of the ovarian artery around the uterine vein functions as a specialized countercurrent vascular transfer system.
• Luteolytic Mechanism: Enables endometrial $\text{PGF}_{2\alpha}$ to diffuse directly from the high-concentration uterine venous blood into the ovarian arterial supply, transporting it straight to the ipsilateral ovary to induce corpus luteum lysis while avoiding $99\%$ metabolic degradation during first-pass transit through maternal lungs (Option 3).

Correct option: (3) Transport PGF2a from the uterus to the ovary