$\begin{array}{l}{\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{CH}\frac{{\mathrm{HgSO}}_4}{\underset{\text{ dil. }{\mathrm{H}}_2{\mathrm{SO}}_4}{ }}\left(\mathrm{A}\right)\\ \\ {\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{CH}\frac{\left(1\right){\mathrm{BH}}_3\cdot \mathrm{THF}}{\left(2\right){\mathrm{H}}_2{\mathrm{O}}_2/{\mathrm{HO}}^{-}}\left(\mathrm{B}\right)\end{array}$

(A) and (B) are Major product and are differentiated by: