Consider the above chemical reaction. Product "A" is:

Step 1: Identify the reaction conditions

Cyclohexyl chloride with methyl substituent + NaOH in water (aqueous)

Aqueous NaOH → $S_N2$ substitution favored (not elimination)

Step 2: Determine the mechanism

$S_N2$ mechanism:

• Backside attack by $\ce{OH-}$
• Inversion of configuration
• Cl replaced by OH

Step 3: Identify the product

Starting material: Chlorocyclohexane with methyl group

Product: Cyclohexanol with methyl group (OH replaces Cl)

The position of OH depends on:

1. Where Cl was originally
2. Stereochemistry (inversion if chiral center)

Step 4: Determine stereochemistry

If the starting material has:

• Cl at C-1
• $\ce{CH3}$ at C-2 (or other position)

After $S_N2$:

• OH at C-1 (inverted configuration)
• $\ce{CH3}$ remains at same position

Option (b) shows cyclohexanol with OH and $\ce{CH3}$ in specific positions, suggesting the correct stereochemical outcome.

Answer: (b)

Key Points:

• Aqueous NaOH → $S_N2$ substitution (primary/secondary halides)
• Alcoholic NaOH → E2 elimination
• $S_N2$ → Inversion of configuration (Walden inversion)
• Cyclohexane conformations: equatorial substituents more stable