Isopropyl alcohol is obtained by reacting which of the following alkenes with conc. $H_2SO_4$ and $H_2O$?

The product $(A)$ of the given alkoxymercuration-demercuration reaction is:

$CH_3-CH=CH_2 + HBr \xrightarrow{\ \ } .........$,the product formed is

With oxalic acid,glycerol at $260\,^\circ C$ gives

Diborane reacts with terminal alkenes to form trialkylboranes. These react with alkaline hydrogen peroxide to form:

Identify the major product $B$ in the given sequence of reactions:
$CH_3-C \equiv CH$ $\xrightarrow{H_2 / Pd-C} A$ $\xrightarrow{(C_6H_5CO)_2O_2 / HBr} B$