Given below are the statements about diborane.
(a) Diborane is prepared by the oxidation of NaBH4 with I2.
(b) Each boron atom is in sp2 hybridized state.
(c) Diborane has one bridged 3 centre-2-electron bond.
(d) Diborane is a planar molecule.
The option with correct statement(s) is :