Hydathodes are the special structures found on the margins and tips of leaves that are responsible for guttation. Guttation is the process by which water is released from the leaves of plants in the form of droplets.

Hydathodes are made up of parenchyma tissue, which is a type of simple plant tissue consisting of thin-walled cells. These cells are capable of storing and transporting water. Hydathodes are usually located at the tips of veins or leaf margins, where they are connected to the xylem vessels that transport water throughout the plant.

When the plant has excess water in its system, hydathodes help in the elimination of this excess water through a process called guttation. Guttation occurs when the plant's root system absorbs more water than the plant can transpire through its stomata. This excess water is pushed up to the leaves and is released through the hydathodes in the form of droplets.

The droplets of water released through the hydathodes contain dissolved minerals and other substances that were present in the xylem sap. Guttation usually occurs during the night or early morning when transpiration rates are low and the atmospheric humidity is high.

In contrast, stomatal pores are small openings found on the surface of leaves and stems that control the exchange of gases and water vapor between the plant and its environment. Stomata play a crucial role in photosynthesis and transpiration.

Nodes, on the other hand, are the points on a stem where leaves, branches, and buds are attached. They are important for plant growth and development.

Therefore, the correct answer is option 'C' - hydathodes. These specialized structures made of parenchyma tissue and water pores are responsible for guttation, the process by which water is released from the leaves of plants in the form of droplets.