The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Characteristic of venous blood flow of lower limb in duplex Doppler is?   (A) Monophasic   (B) Biphasic   (C) Triphasic   (D) Non phasic
['(A) Monophasic <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Monophasic \n (B) Biphasic \n (C) Triphasic \n (D) Non phasic <> possible answers', '  Characteristic of venous blood flow of lower limb in duplex Doppler is? <> context@']