Dimethyl ether when heated with excess $HI$ gives

The reagent used for the preparation of higher ether from halogenated ethers is

Identify the product $(A)$ of the following reaction:
$C_2H_5-O-C_2H_5 + CO \xrightarrow[500 \text{ atm}]{BF_3 / 150^{\circ}C} A$

In the reaction shown below,the products are:

Ethers are prepared from alcohols by Williamson synthesis. Heating ethanol with sulfuric acid at $413 \ K$ gives ethoxyethane. Match the ether compounds in Column-$I$ with the products formed upon heating with $HI$ in Column-$II$.

Column-$I$ (Ether)	Column-$II$ (Product)
$(A)$ $CH_3CH_2-CH(CH_3)-CH_2-OCH_2CH_3$	$(i)$ $CH_3OH + CH_3-C(CH_3)_2-I$
$(B)$ $CH_3CH_2CH_2-O-C(CH_3)_2CH_2CH_3$	(ii) $C_6H_5OH + C_6H_5CH_2I$
$(C)$ $C_6H_5CH_2-O-C_6H_5$	(iii) $CH_3CH_2CH_2OH + CH_3CH_2-C(CH_3)_2-I$
$(D)$ $CH_3-C(CH_3)_2-O-CH_3$	(iv) $CH_3CH_2-CH(CH_3)-CH_2OH + CH_3CH_2I$

In the following reaction sequence,structures of $A$ and $B$,respectively will be