Benzene on reaction with CH3COCl∕AlCl3 gives acetophenone which on reduction with Zn−Hg∕HCl gives ethyl benzene. Bromination of ethyl benzene give 4-bromo-ethylbenzene which upon nitration gives 4-bromo-2-nitroethyl benzene.
[-l-effect of Br directs NO2−at its meta-position] So, option (b) is the correct sequence of reagents used.