$CH \equiv CH + CO + H_2O \xrightarrow{Ni(CO)_4} \text{Product}$. For this reaction,which statement is false?

$R-CH_2-CCl_2-R \xrightarrow{\text{Reagent}} R-C \equiv C-R$
The reagent is

Consider the following reaction sequence:
$CH_3CH_2CH_2CH(Br)CH_2Br + 2NaNH_2 \rightarrow X$
$X \xrightarrow[(ii) (CH_3)_2CHBr]{(i) NaNH_2} Y$
The product $Y$ formed is:

The product $(B)$ is:

What is formed when phenylacetylene reacts with dilute $HgSO_4$ in the presence of $H_2SO_4$?

Schemes $1$ and $2$ describe the sequential transformation of alkynes $M$ and $N$. Consider only the major products formed in each step for both the schemes.
$1.$ The product $X$ is:
$2.$ The correct statement with respect to product $Y$ is:
$(A)$ It gives a positive Tollens test and is a functional isomer of $X$.
$(B)$ It gives a positive Tollens test and is a geometrical isomer of $X$.
$(C)$ It gives a positive iodoform test and is a functional isomer of $X$.
$(D)$ It gives a positive iodoform test and is a geometrical isomer of $X$.