Answer:
Echocardiography
Step-by-step explanation:
Echocardiography is a painless test that uses the sound waves called ultrasonic waves with a frequency exceeding 20 kHz is used to produce images of the heart.
The echocardiography is also known as the ultrasound of the heart which is performed to check the blood clots, the aorta related pictures and the functioning of the valves of the heart.
The picture produced by this echocardiography is known as the echocardiogram and is used to treat heart disease.
Thus, Echocardiography is the correct answer.