I believe the answer you are looking for is they are all body systems found in the human body, or organ systems.
D. Homeostasis- naturally selected function
The answer in agriculture.
<span>In agriculture, fertilizers are commonly used. But when they reach the bay, they could be cause of escessive nutrients. </span><span>Algae use the presence of increased nutrients and enhance their own growth. It is known that they produce an oxygen in the photosynthesis, so it is not a problem while they are still alive. But when these organisms die, their decomposition begins. For the process of decomposition, the oxygen is needed and ultimately it will be depleted from a body of water. This will lead to the death of aquatic animals that depend on oxygen.</span>
