Which of the following pairs are epimers?

AD-glucose and D-mannose
BD-glucose and L-glucose
CD-glucose and D-galactose
DD-glucose and D-fructose

Answer: A, C

Epimers differ in configuration at exactly one stereocentre. Glucose differs from mannose at C-2 and from galactose at C-4. D- and L-glucose are enantiomers, and glucose and fructose are constitutional (functional) isomers.

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