(A) Riding a stationary bicycle or walking on a treadmill is done during a stress test. (B) During an echocardiogram, the client must lie supine while a technician performs the test. To perform the test, the technician uses a conductive gel and a transducer to obtain ultrasound tracings of the heart. (C) A physician need not be present during an echocardiogram, and it is neither invasive nor painful. (D) There is no premedication required for an echocardiogram.