Final answer:
An estuary is a wide area where a river meets the sea, resulting in the mixing of fresh water and salt water. It is a biome with high biodiversity and serves as an important breeding ground for many organisms.
correct answer A
Step-by-step explanation:
An estuary is a wide area at the mouth of a river where it meets the sea.
It is a biome where fresh water from the river mixes with salt water from the ocean, resulting in a diluted (brackish) saltwater.
Estuaries are important breeding grounds for various organisms and have high biodiversity.
Here is the Wailoa, like Pu'uloa (Pearl Harbor), a great example of an estuary, where rivers or streams open out to the sea, and fresh and sea water mix.
correct answer A