Glucose is correctly named as D-(+)-glucose. ‘D’ before the name of glucose represents the
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Configuration
In D-(+)-glucose, ‘D’ gives the relative configuration (the –OH on the lowest chiral carbon lies on the right, as in D-glyceraldehyde), while ‘(+)’ shows that glucose is dextrorotatory. The two are unrelated: D-fructose, for example, is laevorotatory.
Why the other options are incorrect
Option (1) Dextrorotatory — Incorrect. Dextrorotatory is shown by the (+) sign, not by D.
Option (2) Dilute — Incorrect. ‘D’ has nothing to do with the concentration of the solution.
Option (4) Conformation — Incorrect. Conformation refers to arrangements that differ by rotation about single bonds; D refers to configuration.
NCERT (2026-27 edition):
Glucose – …
