The correct answer is: B. Arteries.
A sphygmomanometer is a device used to measure blood pressure. It consists of an inflatable cuff, a pressure gauge, and a stethoscope. The cuff is placed around the upper arm, and the pressure gauge is used to measure the pressure in the artery. The stethoscope is used to listen to the sound of the blood flowing through the artery.
The blood pressure is measured in two numbers: systolic pressure and diastolic pressure. The systolic pressure is the pressure in the artery when the heart beats. The diastolic pressure is the pressure in the artery when the heart is at rest.
Normal blood pressure is considered to be less than 120/80 mmHg. If the systolic pressure is 140 mmHg or higher, or the diastolic pressure is 90 mmHg or higher, the person is considered to have high blood pressure.
High blood pressure is a major risk factor for heart disease, stroke, and kidney disease. It is important to control high blood pressure to reduce the risk of these diseases.
The other options are incorrect because:
- Veins are blood vessels that carry blood back to the heart.
- Eyes are organs of sight.
- Synovial joints are the joints that allow movement in the body.