Exceptions in Blood Vessel Oxygenation

Steps:

• Arteries carry blood away from the heart; most are oxygenated, but pulmonary arteries carry deoxygenated blood to lungs, so not always oxygenated.
• Veins carry blood toward the heart; most are deoxygenated, but pulmonary veins carry oxygenated blood from lungs.
• Evaluate choice labels: arteries always oxygenated (false: no); pulmonary vein deoxygenated (false: no); pulmonary vein oxygenated (true: yes).

Why D is correct:

• D correctly identifies arteries do not always carry oxygenated blood (pulmonary artery exception), pulmonary vein does not carry deoxygenated blood, and pulmonary vein carries oxygenated blood per pulmonary circulation definitions.

Why the others are wrong:

• A incorrectly claims arteries always carry oxygenated blood, ignoring pulmonary artery.
• B provides no evaluation statements.
• C repeats incorrect "no" for pulmonary vein carrying oxygenated blood, which it does.

Final answer: D