Concept:The letter
D in carbohydrates refers to the stereochemical configuration, not optical rotation.
Explanation:In carbohydrates,
D and
L denote the arrangement of groups around the chiral carbon farthest from the carbonyl group.
This system is based on the configuration of
D-glyceraldehyde.
If the
−OH group on the highest numbered chiral carbon is on the right side in the Fischer projection, the sugar is classified as
D.
It does not indicate dextrorotatory nature, because a
D-sugar may be levorotatory or dextrorotatory depending on its specific rotation.
Thus,
D represents the configuration of the molecule, not its optical activity or mode of synthesis.
Answer:Option B: configuration