The picture shows an algal bloom caused by human activities that releases chemicals into the water.

How are organisms affected by algal blooms in bodies of water?

a
The algae absorbs additional sunlight providing aquatic plants with more energy to carry out photosynthesis.
b
The algae blocks sunlight from reaching plants on the bottom of the water, decreasing oxygen output and killing aquatic animals.
c
The algae increases the oxygen content of the water by conducting respiration, increasing the population of aquatic plants.
d
The algae raises the nutrient content of the water increasing the amount of available food that can support populations of organisms.

b

The algae blocks sunlight from reaching plants on the bottom of the water, decreasing oxygen output and killing aquatic animals.