Which of the following best describes an estuary?

• A. A body of water surrounded entirely by land.
• B. A large freshwater lake formed by glacial activity.
• C. A region where freshwater from rivers meets and mixes with saltwater from the ocean.
• D. A deep ocean trench formed by tectonic activity.

Answer: (C)

Verified step by step guidance

1. Understand the definition of an estuary: An estuary is a transitional aquatic ecosystem where freshwater from rivers or streams meets and mixes with saltwater from the ocean.
2. Analyze the options provided in the question. Option 1 describes a landlocked body of water, which does not match the definition of an estuary.
3. Option 2 refers to a freshwater lake formed by glacial activity, which is unrelated to the mixing of freshwater and saltwater characteristic of estuaries.
4. Option 3 matches the definition of an estuary, as it describes the mixing of freshwater from rivers with saltwater from the ocean.
5. Option 4 describes a deep ocean trench formed by tectonic activity, which is unrelated to the concept of an estuary. Therefore, the correct answer is Option 3.