Which one of the following alcohols reacts instantaneously with Lucas reagent?

The reaction of alcohols with Lucas reagent (concentrated HCl and anhydrous $ZnCl_2$) proceeds via an $S_N1$ mechanism involving a carbocation intermediate. The rate of reaction depends on the stability of the carbocation formed.

1. Reactivity Order: Tertiary ($3^{\circ}$) > Secondary ($2^{\circ}$) > Primary ($1^{\circ}$).
2. Observations:

• Tertiary Alcohols: Form highly stable tertiary carbocations and react instantaneously to form alkyl halides, producing immediate turbidity.
• Secondary Alcohols: React within approximately 5 minutes.
• Primary Alcohols: Do not react appreciably at room temperature (turbidity appears only upon heating).

Option 4 ($CH_3CH_2CH_2CH_2OH$) is a primary alcohol and will not react instantaneously. Therefore, the correct option (Option 3) must represent a tertiary alcohol (e.g., 2-Methylpropan-2-ol).