Correct Answer - C
`{:(underset("Ethanol")(C_(2)H_(5)OH),overset(PBr_(3))(rarr),underset((X))(C_(2)H_(5)Br),overset("alC "KOH)(rarr),underset((Y))(CH_(2)=CH_(2))),(,,,," "darr H_(2)SO_(4)),(,,underset((Z))(C_(2)H_(5)OH),overset(H_(2)O)(larr),CH_(3)CH_(2)HSO_(4)):}`