Algal bloom results in

Global warming
Salination
Eutrophication
Biomagnification

The correct answer is C. Eutrophication.

Algal blooms are a rapid increase in the population of algae in a water body. This can happen when there is an excess of nutrients in the water, such as nitrogen and phosphorus. These nutrients can come from runoff from farms, sewage treatment plants, and other sources.

When algae blooms occur, they can block sunlight from reaching other plants and animals in the water. This can lead to the death of these plants and animals. Algal blooms can also produce toxins that can harm humans and animals.

Eutrophication is the process by which a body of water becomes enriched with nutrients. This can lead to an increase in the growth of algae, which can block sunlight and reduce the amount of oxygen in the water. This can kill fish and other aquatic life, and can also make the water unsafe for human use.

Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere. The term is frequently used interchangeably with the term climate change, though the latter refers to both human- and naturally produced warming and the effects it has on our planet. It is most commonly measured as the average increase in Earth’s global surface temperature.

Salinization is the process by which salt accumulates in soil. This can happen when water evaporates from the soil, leaving behind the salt it contains. Salinization can also happen when salt-rich water is used to irrigate crops.

Biomagnification is the process by which the concentration of a substance increases in organisms at higher trophic levels in a food chain. This can happen when organisms consume food that contains the substance, and the substance is not excreted from the body. As the substance moves up the food chain, the concentration of the substance increases in each organism.

In conclusion, the correct answer to the question “Algal bloom results in” is C. Eutrophication.