An ideal solution is prepared at `25^(@)` C by disolving `0.4 kg` of `5` moles liquid A in `20` moles liquid B. The solid is non-volatile and non-electrolyte in the solution. At `25^(@)C`, The vapour pressures of pure liquids A and B are `100` torr and `200` torr respectively and the vapour pressure of solution is `150` torr. The shortest distance between two `A^(+)` ions in the solid is `200sqrt(2)` pm. `(N_(A) = 6 xx 10^(23))`
The molar mass of solid AB is :

Options

A. `100 g//"mol"`
B. `80 g//"mol"`
C. `40 g//"mol"`
D. `160 g//"mol"`

Answer

B