Statement (A) : Diamond is hard. 

Statement (B): Graphite is a good conductor of electricity. 

Statement (C) : Bromine is a liquid non-metal.

Due to long tetrahedral chain geometry is present in diamond, it has very hard nature. In graphite, due to ${\mathrm{Sp}}^2$ hybridization there is one unpaired electron is present at carbon atom. So, that the electricity is passed through electron in graphite. Bromine is a p block element and it is available in liquid form.