Answer:
b. number of aquatic plants
Explanation:
The number of aquatic plants doesn't increase the demand for oxygen in water because<em> these plants take in carbon dioxide rather than oxygen</em>. This means that <u>an increase in their number will not trigger an increase demand for oxygen, </u>rather it will trigger an increase demand for carbon dioxide in its dissolved form.
An<em> increase in the concentration of solid waste</em>, increases the demand for oxygen because it is needed for decomposition.
An<em> increase in aquatic animals</em> will increase the demand for oxygen in its dissolved form because aquatic animals take in oxygen to survive.
An<em> increase in the flow of water</em> increases the demand for oxygen because as water flows, it mixes with air. The more rapid it is, the higher the chance to mix with oxygen.