The correct answer is choice A, B, D and E. These are measures to prevent thrombophlebitis, which is a condition where a blood clot forms in a vein and causes inflammation and pain.

Thrombophlebitis can lead to serious complications such as pulmonary embolism, which is a life-threatening condition where a blood clot travels to the lungs and blocks the blood flow.

Choice A is correct because wearing fitted elastic thromboembolic hose can help compress the veins and improve the blood flow in the legs, reducing the risk of clot formation.

Choice B is correct because drinking 2 to 3 L of fluid per day can help prevent dehydration, which can make the blood thicker and more prone to clotting.

Choice D is correct because elevating your legs above your heart level can help reduce the pressure and swelling in the veins, improving the blood circulation and preventing stasis.

Choice E is correct because smoking can damage the lining of the blood vessels, increase the blood pressure and heart rate, and make the blood more sticky and likely to clot.

Choice C is wrong because crossing your legs when sitting can impair the blood flow in the legs and increase the risk of thrombophlebitis.

It is recommended to avoid prolonged sitting and to move your legs frequently.

Normal ranges for fluid intake are about 2 to 3 L per day for adults, depending on age, weight, activity level and health conditions.

Normal ranges for leg elevation are about 15 to 30 degrees above the heart level.