Concept: Cooked rice spoils mainly due to bacterial action, which first changes its surface and moisture condition.Explanation:Cooked rice left at room temperature quickly supports bacterial growth.The first visible sign of spoilage is usually a slimy or watery appearance.Mould, smell, maggots, and colour changes appear later as spoilage advances.Therefore, sliminess and watery nature are early indicators.Answer: B. sliminess and watery nature.