Which of the following materials is diluted for use in a fog seal?

In the context of fog sealing, the correct choice is water, which is used to dilute the asphalt emulsion before application. Fog seal is a treatment applied to the surface of an asphalt pavement to renew its surface, enhance its appearance, and extend its service life. The asphalt emulsion is typically diluted with water to achieve the right consistency for proper application, allowing it to penetrate the surface effectively while avoiding the potential for pooling or runoff.

The dilution ensures that the emulsion can adequately cover the pavement without becoming overly thick, which could lead to issues such as poor adhesion or uneven application. This diluted mixture is then sprayed onto the surface, where it sets to form a protective layer.

Asphalt cement, fine aggregate, and mineral filler are not typically diluted for use in fog seal. Asphalt cement is usually applied in its standard form without modification. Fine aggregates and mineral fillers are components used in the mixture for paving and do not play a role in the fog seal dilution process. Thus, the only material appropriate for dilution in this context is water.