Correct Answer - B
(A)`B_(2)H_(6)+HCl to B_(2)H_(5)Cl+H_(2)`
(B)`B_(2)H_(6)+NH_(3) underset("low temperature")overset("excess"NH_(3))toB_(2)H_(6).2NH_(3)`
`B_(2)H_(6).2NH_(3)` is ionic compound and comprises `[H_(3)NtoBH_(2)larrNH_(3)]^(+)` and `[BH_(4)]^(-)` ions.
( C)`B_(2)H_(6)+2(Me)_(3)N to 2[Me_(3)N.BH_(3)]`
(D)`B_(2)H_(6)+6H_(2)O to 2B(OMe)_(3)+6H_(2)`
Reactions involved
`(A)2Na[BH_(4)](A)+I_(2)underset("solution")overset("in diglyme")to B_(2)H_(6) , (B)+H_(2)+2NaI`
`B_(2)H_(6)+6H_(2)Oto2H_(3)BO_(3)( C)+3H_(2)`
`B(OH)_(3)+2H_(2)O hArrH_(3)O^(+) + [B(OH)_(4)]^(-) , pK=9.25`
`B_(2)H_(6)(B)+3O_(2)toB_(2)O_(3)+3H_(2)O`
`CoO + B_(2)O_(3)to Co(BO_(2))_(2)`(cobalt metaborate -blue colour bead).