Identify product B in following reaction.

Propanone $$\xrightarrow{\mathrm{Ba}(\mathrm{OH})_2} \mathrm{~A} \xrightarrow[-\mathrm{H}_2 \mathrm{O}]{\Delta} \mathrm{B}$$

Which among the following oxides is acidic in nature?

The units of monosaccharides present in raffinose are

Identify the protein present in nail.