I think it's B because waxing crescent and first quarter is a small part of the full moon
Answer:
They are veins and arteries. The primary function of arteries is to transport highly oxygenated, nutrient-rich blood from our hearts and distribute it to the rest of our body. Veins, on the other hand, are used to pump much-needed blood back to the heart.
You can easily remember it because the scientific name of leech is Hirudinaria. So it secretes anticoagulant named hirudin. Which help it to feed blood longer
