The median cubital vein is the most commonly used blood vessel for drawing blood, due to its accessibility and safety. Other veins, such as the femoral and radial veins, are used less frequently. Avoiding arteries like the median cubital artery is standard practice during blood draws. ;
The median cubital vein is the most commonly used blood vessel to draw blood due to its accessibility, size, and safety. Other veins, such as the femoral and radial veins, are used less frequently, while arteries are avoided during blood draws. Therefore, the correct answer is A. median cubital vein.
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