Which of the following does not reduce Fehling solution?

Identify product $B$ in the following sequence of reactions:
$2 \ CH_3COCH_3$ $\xrightarrow{Ba(OH)_2} A$ $\xrightarrow{\Delta, -H_2O} B$

An aromatic compound $A$ (Molecular formula $C_{8}H_{8}O$) gives a positive $2,4-DNP$ test. It gives a yellow precipitate of compound $B$ on treatment with iodine and sodium hydroxide solution. Compound $A$ does not give Tollen's or Fehling's test. On drastic oxidation with potassium permanganate,it forms a carboxylic acid $C$ (Molecular formula $C_{7}H_{6}O_{2}$),which is also formed along with the yellow compound in the above reaction. Identify $A, B$ and $C$ and write all the reactions involved.

Identify the products $(A)$ and $(C)$ in the following reaction sequence:
$Cyclopentyl-^{14}CN + CH_3MgBr$ $\xrightarrow{H_3O^\oplus} (A)$ $\xrightarrow{NaOI} (B) + (C)$

Propyne was subjected to a reaction with $HgSO_4/dil. H_2SO_4$,which resulted in a product $P$. The product $P$ was heated with $Ba(OH)_2$ to give the product $Q$. The molecular formula of the product $Q$ is

The appropriate reagent for the transformation shown below is: