Which of these statements can be used to characterize blood flow in the human body? a.There is a unidirectional blood flow. b. Arteries always carry oxygenated blood. c. Veins always carry deoxygenated blood. d. Arteries always carry blood away from the heart. e. Veins always carry blood toward the heart.
A) a, c, d, e B) a, b, c, d, e C) a, d, e D) b, c, d, e E) a, b, e