Answer:D. Nerve cord, notochord, gut
When erosion happen it forms small amounts of debris this is then deposited where the water has the least force like a turn in a river this then forms a delta
B. Thermodynamics
The First Law of Thermodynamics (Conservation) states that energy is always conserved, it cannot be created or destroyed. In essence, energy can be converted from one form into another.
Heart and eyes are the answers