Syn dihydroxylation of alkenes by cold, dilute KMnO4

Steps:

• Geraniol contains two C=C bonds and a primary alcohol group.
• Cold, dilute, acidified MnO4- adds two OH groups across each C=C bond via syn addition, forming vicinal diols.
• Excess reagent ensures both double bonds react, yielding a polyol without cleaving C-C bonds.
• The primary alcohol remains unchanged under these mild conditions.

Why A is correct:

• A shows the tetraol product from dihydroxylation of both alkenes, matching the reaction of unsymmetrical alkenes with Baeyer's reagent.

Why the others are wrong:

• B likely depicts cleavage products (carbonyls), which requires hot, concentrated KMnO4.
• C probably shows only one diol, ignoring the excess reagent and second double bond.
• D may represent alcohol oxidation to aldehyde/carboxylic acid, not applicable here.

Final answer: A