Let the speed at which Andy and Ben do the work is A units/hour \& B units/hour respectively.

So, the time taken by Andy and Bob to finish the work would be $$\frac{1}{\mathrm{~A$$ hours \& $$\frac{1}{\mathrm{~B$$ hours respectively. ( $$\because$$ Speed \& Time are inversely proportional when Work is constant)

As we know that Andy and Ben together finish the work in ' $$x$$ ' houirs, so their combined speeds is $$\frac{1}{x}$$, we get $$A+B=\frac{1}{x} \ldots$$ (1) Also it is given that the time taken by Andy to finish the work alone is ' $$y$$ ' hours more than the time taken by Ben alone to finish the work, so we get $$\frac{1}{A}-\frac{1}{B}=y \ldots . .(2)$$

Subtracting equations (1) \& (2) we get $$\frac{2}{B}=x-y \Rightarrow \frac{1}{B}=\frac{x-y}{2}$$ which is equal to the time that Ben would take to finish the work alone.

Hence column (A) has same quantity as column (B), so the answer is (A).