Identify $X, Y$ and $Z$ respectively from the following reactions:

The major product obtained in the following reaction is

$CH_3-CO-CH_3$ $\xrightarrow{I_2/NaOH} \underset{\text{yellow compound}}{(A)} + (B)$ $\xrightarrow{Ag - \text{powder}, \Delta} (C)$ $\xrightarrow{Dil. H_2SO_4/HgSO_4} (D)$
$A, C$ and $D$ are :-

In the reaction scheme shown below,$Q$,$R$,and $S$ are the major products. Identify the correct structure of the products from the given options:
$(P)$ + Succinic anhydride $\xrightarrow{AlCl_3}$ $Q$
$Q$ $\xrightarrow[H_3PO_4]{Zn-Hg/HCl}$ $R$
$R$ $\xrightarrow[(ii) H_3O^+]{(i) CH_3MgBr, (iii) H_2SO_4/\Delta}$ $S$
$(A)$ $S$ is [Structure $A$]
$(B)$ $Q$ is [Structure $B$]
$(C)$ $R$ is [Structure $C$]
$(D)$ $S$ is [Structure $D$]

Which of the following aldehydes gives a red precipitate with Fehling solution?

What will be the major product?