Alcohol types in vicinal diols from alkene dihydroxylation Steps:

• Cold, dilute acidified MnO₄⁻ adds two OH groups syn to the double bond, forming diols.
• But-1-ene (CH₂=CHCH₂CH₃) yields butane-1,2-diol: HOCH₂CH(OH)CH₂CH₃ (primary OH at C1, secondary OH at C2).
• But-2-ene (CH₃CH=CHCH₃) yields butane-2,3-diol: CH₃CH(OH)CH(OH)CH₃ (two secondary OH groups at C2, C3).
• X correct: butane-1,2-diol has primary OH; Y correct: butane-1,2-diol (and butane-2,3-diol) has secondary OH.

Why C is correct:

• X and Y accurately state that at least one diol has a primary OH and at least one has a secondary OH, per alcohol classification (primary: OH on CH₂R; secondary: OH on CHR₂).

Why the others are wrong:

• A. W and Y: W incorrect because butane-2,3-diol has only secondary OH groups, not primary and secondary.
• B. W and Z: Z incorrect because but-1-ene lacks cis-trans isomerism (one =C has two H atoms).
• D. X and Z: Z incorrect because but-1-ene lacks cis-trans isomerism (one =C has two H atoms).

Final answer: C