Answer:
A
Explanation:
Because of the convectional currents
<span>The amount of dissolved oxygen in water may decrease
because of the increase in organic matter in the water. <span>Aquatic organisms breathe and use oxygen. Large amounts of
oxygen are consumed by the decomposition of bacteria (when there are large
amounts of dead matter to decompose, there will be a significant number of
bacteria). Examples: dead organic matter (algae), wastewater, garden waste,
oils and fats, all this results in a decrease in dissolved oxygen in the water.</span></span>
Runner A because they completed it in a less amount of time
The answer is D. If you aren't consistent with your drop positions, then your data may be invalid. To be frank: it basically screws over the experiment.
