If `P^(@)` and `P_(s)` are vapour pressure of solvent and its solution, respectively, `chi_(1)` and `chi_(2)` are mole fractions of solvent and solute, respectively, then
A. `P_(s)=P^(@)//chi_(2)`
B. `P^(@)-P_(s)=P^(@)chi_(2)`
C. `P_(s)=P^(@)chi_(2)`
D. `(P^(@)-P_(s))/P_(s)=chi_(1)/(chi_(1) + chi_(2))`

If `P^(@)` and `P_(s)` are vapour pressure of solvent and its solution, respectively, `chi_(1)` and `chi_(2)` are mole fractions of solvent and solute, respectively, then
A. `P=P_(0)N_(2)`
B. `P=P_(0)N_(1)`
C. `P_(0)=PN_(1)`
D. `P=P_(0)(N_(1)//N_(2))`