The ans of this is...?

Solution :
Phenolphthalein indicator turns the colour for basic solutions to pink colour.
Phenolphthalein indicator doesn't show any change in colour for acidic solutions (remains colourless).
Na₂CO₃ is basic salt (as metal carbonates are basic) : It originates from NaOH (Strong Base) and H₂CO₃ (Weak Acid)
Hence, it will show pink colour with Phenolphthalein indicator.
NH₄Cl is acidic salt : It originates from NH₄OH (Weak Base) and HCl (Strong Acid)
Hence, it will not show any colour change with Phenolphthalein indicator.
Thus, X is Na₂CO₃ and Y is NH₄Cl.
Hence, the correct answer is option (A).