Which of following methods is used to separate wolframite and stannic oxide present in cassiterite?

$$\begin{aligned} & \text { In the reaction, } \\ & \mathrm{MnO}_4^{-1}(a q)+\mathrm{Br}^{-1}(a q) \longrightarrow \mathrm{MnO}_2(s)+\mathrm{BrO}_3^{-1}(a q) \end{aligned}$$

,the correct change in oxidation number of the species involved is

How many isoprene units are present in abscisic acid?

Action of hydrogen iodide on anisole gives,