Concept:Water-holding capacity depends on physical properties that influence pore spaces and water retention.Explanation:Texture affects the size of soil particles and the space between them.Soils with more clay and silt hold more water than sandy soils.Structure determines how soil particles are arranged into aggregates.Good structure improves pore space and helps the soil retain water.Soil pH and colour do not directly control water retention.Hence, the relevant properties are I (Texture) and IV (Structure).Answer:B. I and IV only