Select the suitable reagent for the conversion shown below:

Identify the major product $X$ in the following reaction:
$1,5,5-\text{trimethylcyclohex-1-ene} \xrightarrow{N.B.S., h\nu} X$

$CH_3 - CH = CH_2 \xrightarrow[(2) CH_3CO_2T]{(1) THF : BD_3} (A)$; Product $(A)$ of the above reaction is

Which reaction is known as Kharash reaction?

$But-1-ene$ may be converted to $butane$ by reaction with:

$HCl$ does not show the peroxide effect because the reaction mechanism involves the following steps:
$CH_3-CH=CH_2 + \dot{X} \to CH_3-\dot{C}H-CH_2X$ $(I)$
$CH_3-\dot{C}H-CH_2X + HX \to CH_3-CH_2-CH_2X + \dot{X}$ $(II)$
Why does $HCl$ fail to undergo this reaction?