Mole fraction of the component 'A' in vapour phase is X and mol fraction of component 'A' in liquid mixture is Y $(P_A^0$=vapour pressure of pure A,$P_A^0$=vapour pressure of pure B) then total vapour of the liquid mixture is

$\begin{array}{1 1}(a)\;\large\frac{P_B^0Y}{X}\\(b)\;\large\frac{P_B^0X}{Y}\\(c)\;\large\frac{P_A^0X}{Y}\\(d)\;\large\frac{P_A^0Y}{X}\end{array}$

By equating Raoult's and Dolton's partial pressure expressions
As per Dolton
Partial pressure $=PX$-----(1)
As per Raoults
Partial pressure $=P_A^0Y$-----(2)
(1)=(2)
$PX=P_A^0Y$
$P=\large\frac{P_A^0Y}{X}$
Hence (d) is the correct answer.