Final answer:
The highlighted areas in the image likely represent drainage basins, which are land areas that collect precipitation and drain into a river or other water body.
Step-by-step explanation:
The correct answer to the question is a) Drainage basins. A drainage basin is defined as the area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. The highlighted areas in an image of topographic features are likely representing drainage basins, which can vary greatly in size and are separated from each other by a drainage divide. It is important to understand that every drop of water that falls within a drainage basin ultimately makes its way to the main river, contributing to the streamflow and affecting river discharge. This concept is essential in the field of environmental biology and hydrology, as it plays a vital role in the hydrological cycle and influences water resource management.