Answer:
b. (CH3CH2)2C(CH3)OH
Step-by-step explanation:
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In this case, since the order of reactivity of alcohols is intimately related with their degree of substitution, being the tertiary alcohols the most reactive and the primary alcohols the least reactive since the adjacent substituents promote the -OH substitution or elimination, among the options, b. (CH3CH2)2C(CH3)OH which is a tertiary alcohol due to the presence of the OH at the central carbon atom bonded with two ethyl radicals and one methyl radical will react more rapidly with HBr than the other ones which are primary and secondary.
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