Final answer:
The hydrologic cycle stage that can most directly cause algal blooms is runoff, which carries fertilizers and nutrients into bodies of water, leading to excessive algal growth and possible dead zones.
"the correct option is approximately option E"
Step-by-step explanation:
The stage of the hydrologic cycle that can be the most direct cause of algal blooms is runoff. When we look at the flow of freshwater from precipitation, such as rain or melting ice, it travels over the surface of the land as surface runoff.
This water can collect and carry with it various substances, including fertilizers and other nutrients from farming fields, gardens, and urban areas, into streams, rivers, and eventually into larger bodies of water like lakes and oceans.
Tthe added nutrients, particularly nitrogen and phosphorus from these fertilizers, often lead to excessive growth of algae.
This condition, known as eutrophication, creates algal blooms that can deplete the oxygen in the water and harm aquatic life, leading to dead zones. Therefore, among the given options, e) Runoff is the correct answer to the question of which stage of the hydrologic cycle can be the most direct cause of algal blooms.