Final answer:
The carbohydrates-rich zone at the surface of most eukaryotic cells is known as the D) glycocalyx. It is important for cell identification, immune system recognition, and facilitating interaction with the watery environment.
Step-by-step explanation:
The carbohydrates-rich zone at the surface of most eukaryotic cells is known as the glycocalyx. The glycocalyx, which means "sugar coating", is a layer composed of carbohydrate components of both glycoproteins and glycolipids.
This layer is highly hydrophilic, meaning that it attracts water, which aids the cell in interacting with its environment and obtaining substances dissolved in water.
The recognition function of the glycocalyx is crucial as it allows the immune system to differentiate between body cells ("self") and foreign cells or tissues ("non-self").
It is also essential for cell identification, embryonic development, and is used in cell-to-cell attachments to form tissues. Therefore, the correct answer to the question is D) Glycocalyx.