To solve this problem, we need to identify which carbohydrate among the given options is non-reducing. Let's analyze each option:$\newline \bullet$Maltose:$\newline$ - Maltose is a disaccharide composed of two glucose units linked by an alpha-1,4-glycosidic bond.$\newline$ - It has a free anomeric carbon on one of the glucose units, making it a reducing sugar.$\newline \bullet$Sucrose:$\newline$ - Sucrose is a disaccharide composed of glucose and fructose linked by an alpha-1,2-glycosidic bond.$\newline$ - Both anomeric carbons are involved in the glycosidic bond, so there is no free anomeric carbon.$\newline$ - Therefore, sucrose is a non-reducing sugar.$\newline \bullet$Lactose:$\newline$ - Lactose is a disaccharide composed of glucose and galactose linked by a beta-1,4-glycosidic bond.$\newline$ - It has a free anomeric carbon on the glucose unit, making it a reducing sugar.$\newline \bullet$Ribose 5-phosphate:$\newline$ - Ribose 5-phosphate is a monosaccharide and has a free anomeric carbon.$\newline$ - Therefore, it is a reducing sugar.$\newline$Based on the analysis, the only non-reducing carbohydrate among the options is sucrose.$\newline$Thus, the correct option is Option 2: Sucrose.