The Z-configuration in the following is

The order of priority(based on atomic no.) of groups attached to double bonded carbon isIn Options(1) & (2) ,  -H < -CH3 (in case of C1)                                  -C2H5 < -C3H7 (in case of C2)In Option(3) ,  -H <  F (in case of C1)                       -Br < -Cl (in case of C2)If two high priority groups are of the same side to the double bond, then it is  Z-isomer.If two high priority groups are of the opposite side to the double bond, then it is E-isomer.∴ Option(2) represents Z-isomer.