Final answer:
Laparoscopy is the most accurate diagnostic method for confirming an ectopic pregnancy, as it allows direct visual confirmation.
Step-by-step explanation:
The most accurate diagnostic method for an ectopic pregnancy is d) Laparoscopy. Although a transvaginal ultrasound and Beta-hCG blood test can provide important indicators and are commonly used for initial evaluation, laparoscopy is the definitive method for diagnosis. During a laparoscopy procedure, a camera is inserted through the abdominal wall, allowing the physician to visually inspect and confirm the presence of an ectopic pregnancy directly.