<prompt> Most valuable diagnostic test in case of suspected ectopic pregnancy:Serial b-hCG revelsTransvaginal USGProgesterone measurementCuldocentesis  <response>: Ans. is b, i.e. Transvaginal USGRef. Dutta Obs. 7e, p 182, 183; Williams Gynae 1e, p 162, 163; Novak 14e, p 611; Williams Obs. 22e, p 259, 23e, p 242, 43As explained earlier transvaginal ultrasound is the best available diagnostic modality for diagnosing ectopic pregnancy. Vaginal sonography yields correct pre-operative diagnosis of ectopic pergnancy in 91 cases. It decreases the need for diagnostic laparoscopy or curettage or both to establish the diagnosis of ectopic pregnancy --Williams Gynae 1e, p 163Vaginal sonography has become the imaging method of choice. --Williams Obs. 22e, p 259 