The correct sequence of reagents for the following conversion will be:

The end product $(C)$ in the following sequence of reactions is:
$HC \equiv CH$ $\xrightarrow[20\% \ H_2SO_4]{1\% \ HgSO_4} A$ $\xrightarrow[H_2O]{CH_3MgX} B$ $\xrightarrow{[O]} (C)$

In the following sequence of reactions, compound $M$ is:
$M$ $\xrightarrow{CH_3MgBr} N + CH_4 \uparrow$ $\xrightarrow{H^+} CH_3COCH_2COCH_3$

Which of the following compounds gives the iodoform test?

Which of the following aldehydes is most reactive towards nucleophilic addition reactions?

Consider the following reaction sequence:
$\text{But-2-ene}$ $\xrightarrow{\text{ozonolysis}} X$ $\xrightarrow[(ii) H_3O^+]{(i) CH_3MgBr} Y$ $\xrightarrow[573 \ K]{Cu} Z$
The correct statements about $Z$ are:
$I$. It gives yellow precipitate with $I_2$ and $NaOH$ solution.
$II$. It undergoes disproportionation reaction in the presence of concentrated $NaOH$ solution.
$III$. It undergoes Wolff-Kishner reduction.
$IV$. It forms red precipitate with Fehling's reagent.