Identify X, Y and Z in the following synthetic scheme and write their structures. The product Z when treated with HBr gives compound A which on reductive ozonolysis gives formaldehyde as one of the product. Deduce the entire scheme.
`CH_(2)=CH-Br overset("(i) Mg/ ether")to X overset((ii)CO_(2))underset((iii) H_(3)^(+)O)toY overset(LiAlH_(4))to Z overset(HBr)toA overset(O_(2)//H_(2)O // Zn)to HCHO +` other product

Explanation