This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Radiology
Duplex ultrasonography combines: 
Select and explain. 
A. A-mode imaging and pulse-wave Doppler examination, B. B-mode imaging and pulse-wave Doppler examination, C. M-mode imaging and power Doppler examination, D. M-mode imaging and waveform analysis
B: B-mode imaging and pulse-wave Doppler examination
Answer: B: B-mode imaging and pulse-wave Doppler examination 
Explanation: Ans. B. B-mode imaging and pulse-wave doppler examinationAn objective assessment of the severity of disease is obtained by noninvasive techniques. These include digital pulse volume recordings, doppler flow velocity waveform analysis, duplex ultrasonography (which combines b-mode imaging and pulse-wave doppler examination), segmental pressure measurements, transcutaneous oximetry, stress testing (usually using a treadmill), and tests of reactive hyperemia.