Why is chloroform stored in dark-colored bottles?

Alcoholic potash is used to bring about

Assertion $(A)$: $1-$Bromopentane reacts with $AgCN$ to give pentylisocyanide.
Reason $(R)$: $AgCN$ is mainly ionic in nature.

$ . . . . . . $ compound is slowly oxidized by air in the presence of light to an extremely poisonous gas, carbonyl chloride.

The reaction of $4-methylcyclohexyl$ halide with $OH^-$ via the $S_N2$ mechanism produces $A$. Identify $A$.

In the following reactions,
$(i) CH_3-CH(CH_3)-CH(OH)-CH_3 \xrightarrow{H^{+}/\text{heat}} A \text{ [Major product]} + B \text{ [Minor product]}$
$(ii) A$ $\xrightarrow[\text{in absence of peroxide}]{HBr, \text{dark}} C \text{ [Major product]} + D \text{ [Minor product]}$
the major products $(A)$ and $(C)$ are respectively: