Which of the following is a laboratory method for the preparation of acetyl chloride?

Compare the two methods shown for the preparation of carboxylic acids.
Method $1$: $RBr$ $\xrightarrow[diethyl \ ether]{Mg} RMgBr$ $\xrightarrow[2. \ H_3O^{+}]{1. \ CO_2} RCO_2H$
Method $2$: $RBr$ $\xrightarrow{NaCN} RCN$ $\xrightarrow[heat]{H_2O, HCl} RCO_2H$
Which one of the following statements correctly describes this conversion for the given substrate ($1$-bromoadamantane)?

Identify the product $Z$ in the series
$CH_3CN$ $\xrightarrow{Na + C_2H_5OH} X$ $\xrightarrow{HNO_2} Y$ $\xrightarrow[H_2SO_4]{K_2Cr_2O_7} Z$

The product obtained when acetic acid is treated with phosphorus trichloride is

Benzotrichloride reacts with milk of lime to form

Identify product $C$ in the following conversion sequence: $m$-Hydroxybenzaldehyde $\xrightarrow[\text{Protection of } -OH \text{ group}]{C_6H_5CH_2Cl} A$ $\xrightarrow{[O]} B$ $\xrightarrow{\text{deprotection}} C$.