The correct answer is option 2: Sandy soil. Watermelons grow best in sandy soil because it has good drainage properties, allowing excess water to pass through easily. Sandy soil also has a loose texture, which enables the roots of watermelon plants to penetrate and spread easily. It warms up quickly in the spring, which is beneficial for the germination and growth of watermelon seeds. Additionally, sandy soil retains heat well, creating a favorable environment for watermelons to thrive. While other soils like alluvial, black, and laterite can also support the growth of watermelons to some extent, they might have less efficient drainage and heat retention compared to sandy soil. Therefore, watermelons flourish and produce better yields when cultivated in sandy soil.