Concept:Cane sugar (sucrose) must be hydrolysed by an acid or an enzyme before glucose can be detected.Explanation:Test tube I contains only cane sugar and water, so no significant hydrolysis occurs and glucose is not produced.Test tube II contains diluted acid, which hydrolyses cane sugar into glucose and fructose.Test tube III contains the degrading enzyme, which also hydrolyses cane sugar into glucose and fructose.Therefore, glucose will be detected in test tubes II and III only.Answer:B. II and III only