Task: Question Answering
Input (English): Question: The first stage of the mechanism of dehydration of cyclohexanol with H2SO4 is: 
 Options:  <1> Loss of OH-. <2> Formation of an ester sulfate. <3> Protonation of alcohol. <4> Loss of H + by alcohol. <5> Elimination of H2O from alcohol.
Output (English): 3