Step 1: Understanding the Concept:
Diagnostic pregnancy testing, reproductive placental endocrinology, and obstetrical pharmacological interventions.
Step 2: Detailed Explanation:
Matching theriogenology concepts in List I with descriptions in List II:
- A. Cuboni's Test: Chemical fluorometric test detecting urinary IV. Estrogen (estrone sulfate) for pregnancy diagnosis in mares after day 120.
- B. Endometrial Cups: Transient equine placental structures that synthesize and secrete III. eCG (Equine Chorionic Gonadotropin).
- C. Oxytocin: The primary uterotonic peptide used for the I. Induction of parturition in mare (diluted slow IV infusion).
- D. Tocolysis: Pharmacological II. Prevention of uterine contractions and premature labor using $\beta_2$-agonists (clenbuterol) or calcium channel blockers.
Matching sequence: A - IV, B - III, C - I, D - II.
Step 3: Final Answer:
Therefore, the correct matching is A - IV, B - III, C - I, D - II, corresponding to option (D).