Which one of the following compound will show addition of HBr to alkene according to markownikoff's rule?

When a mixture of two different alkyl halides reacts with metallic sodium in dry ether, the formation of a possible number of alkanes are-

Identify the product of reforming reaction of n-hexane in the presence of $\text{V}_2\text{O}_5$ over alumina.

An element crystallises in fcc unit cell with cell edge length of $3.608 \times 10^{-8}$ cm, the density of element is $8.92 \text{ gcm}^{-3}$. Calculate the atomic mass of element ($\text{N}_A = 6.022 \times 10^{23}$).