Answer the following question given this paragraph: 

In a marine ecosystem, algae are the producers. Through photosynthesis, they provide glucose for the ecosystem. So, can too much algae be a bad thing? Eutrophication is an over-enrichment of chemical nutrients in a body of water. Usually these nutrients are the nitrogen and phosphorous found in fertilizers. Run-off from lawns or farms can wash fertilizers into rivers or coastal waters.


Q: Through this process, algae provide glucose for the ecosystem?

 Choices:

- spermatogenesis

- glycolysis

- GLUCOPHAGE

- photosynthesis

A:
photosynthesis
