Q: What can be thought of as the most biologically productive regions on earth?


Read this paragraph and choose the correct option from the provided answers:

An estuary is a partly enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the ocean. Estuaries can be thought of as the most biologically productive regions on Earth, with very high biodiversity. Estuaries are zones where land and sea come together, and where fresh and salt water meet.

 Choices:

- swamps

- forests

- coasts

- estuaries


A:
estuaries