D .............. im pretty sure its this one :)
Answer:
the balance is everything must have a process of living and dying in an ecosystem. such as, an animal killing another animal for prey to eat it, that is a process. in a water ecosystem, fish lay eggs and come out and usually get eaten by a bigger animal, as they grow up, usually by bigger fish itself such as the Grayling.
Explanation:
The right option is d) bubbles
The production of bubbles when baking soda mixes with an acid such as vinegar is the observation that indicated a chemical property of the baking soda.
Baking soda (also known as sodium bicarbonate) is a nonflammable, white crystalline powder. Baking soda is odorless, and alkaline. Baking soda reacts with vinegar (acetic acid) to produce carbon dioxide (a gas), water, sodium ion and acetate ion. Baking soda is used for many purposes such as; as an antacid for treating indigestion, for baking, in fire extinguishers, as a water softener, as a pesticide, and to remove dirts from materials.
Homogenous mixture, or a solution.