Q: Context: Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart.

Question: do veins carry blood to the heart or away?
Let's give stream of consciousness below

To answer the question, consider the following: Veins are blood vessels that carry blood toward the heart. So the answer is toward.