Final answer:
Excess chlorophyll in the creek can be due to increased sunlight exposure, high levels of dissolved oxygen, and elevated levels of nitrates and phosphates, promoting the growth of algae and phytoplankton. The correct options are a, c and d.
Step-by-step explanation:
The presence of excess chlorophyll in the creek can be attributed to various factors such as increased sunlight exposure, high levels of dissolved oxygen, and elevated levels of nitrates and phosphates. These factors promote the growth of algae and phytoplankton, which contain chlorophyll and undergo photosynthesis.
Increased sunlight exposure provides the necessary energy for photosynthesis, while high levels of dissolved oxygen and nutrients like nitrates and phosphates support the growth of algae and phytoplankton.
Hence, Options a, c and d are correct.