Correct Answer - B
`2C_2H_6+Br_2rarr2C_2H_5Br+HBroverset(2Na)toC_4H_(10)`
`12xx4+10=58gm`
58 gm of n-butene `implies2xx22.4` litre of `C_2H_6` at STP
i.e., `2xx22.4xx(100)/(85)xx(100)/(90)`
`=58.56` litre at STP
`58gm` of n-butate`=58.56` litre
`55gm` of n-butane`=55.5` litre