$X$, $Y$ and $Z$ are three different halogens. The table gives the outcomes of nine experiments in which aqueous solutions of $X_2$, $Y_2$ and $Z_2$ were added separately to distinct aqueous solutions containing $X^-$, $Y^-$ and $Z^-$ ions. Which row in the table below shows the ions $X^-$, $Y^-$ and $Z^-$ arranged in decreasing order of their reducing power?
- A$X^-$, $Y^-$, $Z^-$
- B$X^-$, $Z^-$, $Y^-$
- C$Y^-$, $Z^-$, $X^-$
- D$Z^-$, $X^-$, $Y^-$