High Volatility of Solvent is associated with which asphalt practice?

Answer: C — Tack Coats, Surface Treatment

Rapid drying of the coating is essential for bonding between layers. When solvent is highly volatile, it evaporates quickly, thinning the asphalt for easy application and then leaving a thin, tacky film that provides a good bond without remaining wet. This rapid evaporation is exactly what you want in tack coats and surface treatments, which are applied as bonding or seal layers between the existing pavement and the new course. Dust control and paving don’t rely on a fast-evaporating solvent in the same way—the former uses binding agents to control dust, and the latter uses hot mix asphalt without a rapid-evaporation solvent action.