Solution

Statement A: Organic matter in the soil improves soil fertility and nutrient availability. This statement is true. It enhances the soil's ability to retain moisture, improves soil structure, promotes microbial activity, and increases nutrient availability to plants. Statement B: Sandy soil having a high water-holding capacity is incorrect. Sandy soil typically has larger particles, resulting in larger pore spaces between them. These larger pores allow water to drain quickly through the soil, leading to poor water retention and limited water availability for plants. Statement C: Soil pH affecting nutrient availability to plants is true. Soil pH significantly influences the solubility and availability of nutrients to plants. Different nutrients have varying solubility across different pH levels.