$n$-butane on heating with a catalytic mixture of $AlCl_3$ and $HCl$ gives:

Given below are two statements:
Statement $I$: Methane can be prepared by decarboxylation of sodium ethanoate,Kolbe's electrolysis of sodium acetate and reaction of $CH_3MgBr$ with water.
Statement $II$: Methane cannot be prepared from unsaturated hydrocarbons and by Wurtz reaction.
In the light of the above statements,choose the correct answer from the options given below.

Which reactive intermediate is involved in the following reaction?
$2-\text{methylbutane} \xrightarrow{Br_2, hv} 2-\text{bromo}-3-\text{methylbutane}$ (not the major product)

Identify product $P$ in the following reaction: $C_2H_5MgBr + NH_3 \rightarrow P$

Choose the chain terminating step.
$(1)$ $H_2 \to H^{\bullet} + H^{\bullet}$
$(2)$ $Br_2 \to Br^{\bullet} + Br^{\bullet}$
$(3)$ $Br^{\bullet} + HBr \to H^{\bullet} + Br_2$
$(4)$ $H^{\bullet} + Br_2 \to HBr + Br^{\bullet}$
$(5)$ $Br^{\bullet} + Br^{\bullet} \to Br_2$

In the given compounds,which has the highest boiling point $:-$