In the following compounds, the ones that give positive iodoform test are

Propyne was subjected to a reaction with $\mathrm{HgSO}_4 /$ dil. $\mathrm{H}_2 \mathrm{SO}_4$, which resulted in a product $P$. The product $P$ was heated with $\mathrm{Ba}(\mathrm{OH})_2$ to give the product $Q$. The molecular formula of the product $Q$ is

$$ \text { The major product in the following reactions is } $$

$$ \text { The major product of the following reaction is } $$