Find out the structure of 'A' :

Find out the structure of 'X':

Compound A treated with NaNH_2 followed by CH_3CH_2Br gave compound B. Partial hydrogenation of compound B produced compound C, which on ozonolysis gave a carbonyl contpound D. (C_3H_2O) . Compound D did not respond to iodofom test with I_2//KI and NaOH. Find out the structures of A, B, C & D.

Find out structure of B :

Find out structure of B.

Find out structure of Y:

Find out the structure of lactose: