Answer: C.Adheison
Step-by-step explanation:
Let's begin by understanding the following definitions:
Cohesion
Is the attraction that molecules have for others of their same type.
Adhesion
Is the attraction that molecules have for others of different type by intermolecular forces.
In this sense, water have both properties, it can stick to itself through hydrogen bonds (cohesion) and can also stick to a glass (or a surface) due to adhesion.
So, while Cohesion is the force of attraction between water particles and the responsible of forming water drops, Adhesion is the interaction between water particles and the surfaces.
Therefore, when water drops stick to the surface is due adhesion.