In the reaction of hypobromite with amide, the carbonyl carbon is lost as:

The reaction of an amide with hypobromite is the Hofmann bromamide degradation (Hofmann rearrangement). In this reaction, an amide $$\text{RCONH}_2$$ is treated with $$\text{Br}_2$$ in aqueous $$\text{NaOH}$$ (which generates $$\text{OBr}^-$$, the hypobromite ion).

The mechanism proceeds through formation of an N-bromoamide, which undergoes base-induced rearrangement to an isocyanate $$\text{R-N=C=O}$$. In the aqueous alkaline medium, the isocyanate is hydrolysed to a carbamic acid intermediate that decomposes to give the primary amine $$\text{RNH}_2$$ and $$\text{CO}_2$$. Since the reaction is carried out in strongly basic (NaOH) solution, the $$\text{CO}_2$$ is immediately absorbed to form the carbonate ion $$\text{CO}_3^{2-}$$.

Thus the carbonyl carbon of the original amide is lost as $$\text{CO}_3^{2-}$$, which is option (1).