The question asks to identify the property of a fluid responsible for the attraction between its own molecules.

Defining Fluid Properties

Fluids exhibit various properties related to the forces between their molecules. Let's examine the options:

• Adhesion: This is the tendency of dissimilar particles or surfaces to cling to one another. It involves attraction between the molecules of *different* substances.
• Cohesion: This is the tendency of similar or identical particles or surfaces to cling to one another. It specifically refers to the attraction between the molecules of the *same* substance.
• Viscosity: This property measures a fluid's resistance to flow. It's related to internal friction between fluid layers.
• Compressibility: This is the ability of a substance (like a fluid) to reduce its volume when pressure is applied.

Identifying the Correct Property

The question explicitly mentions the attraction between a fluid's own molecules. This directly matches the definition of cohesion.

Therefore, cohesion is the property by which a fluid's own molecules are attracted to each other.