B. the increase in algae population reduces oxygen in the water
**The correct answer option B **
The excess of nutrients in water leads to the formation of algal bloom. The nutrients favor the growth of algae.
This growth of algae is harmful to the other organism living in the water. This is because the growth of algae on the upper surface of water does not allow the oxygen and light to reach the organism inside water.
This depletion of oxygen in water kills the organism inside water.
Excess nutrients from fertilizers cause algal blooms, which block sunlight and lead to oxygen depletion in aquatic ecosystems. This process can create dead zones, resulting in the death of various aquatic organisms. Thus, option B - the increase in algae population reduces oxygen in the water - is correct.
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