The Friedel - crafts alkylation reaction will give propyl phenyl ketone which on further
Clemmensen's reduction will give butyl benzene. C6H6+CH3CH2CH2COClAlCl3C6H5COCH2CH2CH3Zn−Hg/HClButylbenzeneC6H5CH2CH2CH2CH3
Rest other will give 2-phenylbutane as in them rearrangement of carbocation is possible.