An organic compound 'X' showing the following solubility profile is :

The major product of the following reaction is :

In the following compounds, the decreasing order of basic strength will be :

The vapour pressures of pure liquids A and B are 400 and 600 mmHg, respectively at 298 K on mixing the two liquids, the sum of their initial volume is equal ot the volume of the final mixture. The mole fraction of liquid B is 0.5 in the mixture, The vapour pressure of the final solution, the mole fractions of components A and B in vapour phase, respectively are :