$CH_3-C\equiv CH \xrightarrow{O_3/Zn, H_2O_2} \text{Product}$ The product in the above reaction is

An acyclic hydrocarbon $P$ with molecular formula $C_6H_{10}$ produces acetone as the only organic product through the following reaction sequence,where $Q$ is an intermediate organic compound:
$P (C_6H_{10})$ $\xrightarrow[(ii) NaBH_4/ethanol, (iii) dil. acid]{(i) dil. H_2SO_4/HgSO_4} Q$ $\xrightarrow[(ii) O_3, (iii) Zn/H_2O]{(i) conc. H_2SO_4 (catalytic amount), (-H_2O)} 2 CH_3COCH_3$
$1.$ The structure of compound $P$ is:
$(A)$ $CH_3CH_2CH_2CH_2-C \equiv C-H$
$(B)$ $H_3CH_2C-C \equiv C-CH_2CH_3$
$(C)$ $(CH_3)_2CH-C \equiv C-CH_3$
$(D)$ $(CH_3)_2CH-C \equiv C-H$
$2.$ The structure of compound $Q$ is:
$(A)$ $(CH_3)_2CH-CH(OH)-CH_2CH_3$
$(B)$ $(CH_3)_2CH-CH(OH)-CH_3$
$(C)$ $(CH_3)_2CH-CH_2CH(OH)CH_3$
$(D)$ $CH_3CH_2CH_2CH(OH)CH_2CH_3$
Identify the correct options for $1$ and $2$.

Which reaction is correct for the conversion of chloroform to acetylene?

$[P]$ $\xrightarrow{Br_{2}} C_{2}H_{4}Br_{2}$ $\xrightarrow{NaNH_{2}/NH_{3}} [Q]$
$[Q]$ $\xrightarrow{20 \% H_{2}SO_{4}, Hg^{2+}, \Delta} [R]$ $\xrightarrow{Zn-Hg/HCl} [S]$
The species $[P], [Q], [R]$ and $[S]$ respectively are:

$Ph-C \equiv CH \xrightarrow[MeOH]{MeO^{-}}$ The major product of the reaction is:

Which of the following has the shortest $C-C$ bond length?