The semicarbazone of cyclobutanone is represented as:

Which of the following does not give a yellow solid on treatment with sodium hypoiodite?

Write about the oxidation reaction of methyl ketone compounds $(R-CO-CH_3)$ by the haloform reaction or write a note on the Haloform test.

$Ph-CH_3$ $\xrightarrow{CrO_2Cl_2} (A)$ $\xrightarrow{conc. KOH} Ph-CH_2OH + (B)$
Product $(B)$ of the above reaction is:

$Ph_2CH-C(=O)H \xrightarrow{\text{aqueous acid}} (A) (81\%) + \text{enol} (2\%) + \text{aldehyde} (17\%)$. Product $(A)$ of the above reaction will be:

Which one is most reactive towards nucleophilic addition reaction?