<s>[INST] context: Approach for Post menopausal Bleeding in a woman Office endometrial aspiration biopsy is the accepted first step in evaluating a patient with abnormal uterine bleeding or suspected endometrial pathology. The diagnostic accuracy of office-based endometrial biopsy is 90% to 98% whencompared with subsequent findings at dilation and curettage (D&C) or hysterectomy TVS is at best an adjuvant which helps in the diagnosis of endometrial cancer but 'NOT' the best first step Novaks Gynecology: Transvaginal ultrasonography may be a useful adjunct to endometrial biopsy for evaluating abnormal uterine bleeding and selecting patients for additional testing. Transvaginal ultrasonography, with or without endometrial fluid instillation (sonohysterography), may be helpful in distinguishing between patients with minimalendometrial tissue whose bleeding is related to perimenopausal anovulation or postmenopausal atrophy and patients with significant amounts of endometrial tissue or polyps who are in need of fuher evaluation. The finding of an endometrial thickness greater than 4 mm, a polypoid endometrial mass, or a collection of fluid within theuterus requires fuher evaluation. Hysteroscopy guided biopsy, if utilized, is the single best investigation for assesment of the uterus [/INST] question: Most useful investigation in a 55-year-old postmenopausal woman with DM and HTN who has presented with postmenopausal bleeding is: | options: A: Pap smear B: Endometrial Biopsy C: Transvaginal ultrasound D: Ca-125 estimation | answer: B </s>