Epimer combination (s) is/are: (A) D-glucose & D-fructose, (B) D-mannose & D-talose, (C) D-glucose & D-mannose, (D) D-glucose & D-gulose
Answer is C. When sugars are different from one another, only in configuration with regard to a single carbon atom, other than reference carbon atom, they are called epimers\Ref: DM Vasudevan, 7th edition, page no: 71