$\mathrm{Propene} \stackrel{{\mathrm{H}}_3{\mathrm{O}}^{+}}{\to } \mathrm{A} \stackrel{\mathrm{conc}.{\mathrm{H}}_2{\mathrm{SO}}_4}{\to } \mathrm{B} \underset{\mathrm{b}){\mathrm{H}}_2{\mathrm{O}}_2/{\mathrm{OH}}^{-}}{\overset{\mathrm{a}){\mathrm{B}}_2{\mathrm{H}}_6/\mathrm{THF}}{\to }} \mathrm{C}. \mathrm{A} \mathrm{and} \mathrm{C} \mathrm{are}$

Propene on acidic hydration gives isopropyl alcohol(A),  markovnikoff product

Dehydration of A gives  propene(B).

Propene on hydroboration oxidation gives n- propyl alcohol(C). Hydroboration oxidation is antimarkovnikoff addition of water to alkene.

A and C are positional isomers