Step 1: Understand the function of arteries in the circulatory system. Arteries are blood vessels that carry blood away from the heart to various parts of the body. This is a defining characteristic of arteries.
Step 2: Compare the structure of arteries to veins. Arteries have thicker walls than veins because they need to withstand higher pressure from the blood being pumped by the heart.
Step 3: Clarify the misconception about oxygen content in arteries. While most arteries carry oxygen-rich blood, the pulmonary arteries are an exception as they carry oxygen-poor blood from the heart to the lungs for oxygenation.
Step 4: Address the presence of valves. Unlike veins, arteries do not contain valves because the high pressure in arteries prevents backflow of blood.
Step 5: Review the options provided in the question and identify the correct statement based on the characteristics of arteries. The correct answer is: 'They carry blood away from the heart.'