A scientist studies the effects of excess nitrogen on a pond ecosystem. The scientist collects samples of pond water, adds fertilizer, and measures the growth of algae versus time. The graph shows the results of the study. Information
A line graph. Short description, A line graph.,Long description,
The graph is entitled Time versus Algal Growth. The x-axis is labeled Time in days and the y-axis is labeled Algal Growth and shows a scale in shades of green from clear, then light to dark. The line shows that as time increases, algal growth increases significantly and color moves from light to dark, eventually leveling off at a dark green.

Question
Fish that live in the pond feed on the algae and other aquatic plants. An increase in algae can cause a drop in the amount of dissolved oxygen in the water.

What is the ,begin emphasis, most, end emphasis, likely long-term effect on the fish in the pond as the algae population grows?

Answer options with 4 options
A.
A decrease in the fish population if the dissolved oxygen drops below their requirements.

B.
An increase in the fish population if the added fertilizer causes more aquatic plant growth.

C.
A decrease in the fish population if they cannot compete with plants for the dissolved oxygen.

D.
An increase in the fish population if the added fertilizer provides fish with additional nutrients.