Step 1: Recall what volatilization means. Volatilization is the escape of a compound from a liquid or solid surface into the gas phase. Step 2: Identify the property that governs this escape. A compound's vapor pressure tells us how readily its molecules leave the liquid or solid surface and enter the air at a given temperature. Step 3: Compare with the other factors. Soil texture, soil moisture and organic carbon content can influence how strongly a pollutant is held or diluted, but the compound's own vapor pressure is what fundamentally decides how easily it volatilizes. \[ \boxed{\text{Vapor pressure of the compound}} \]