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

,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,

Which among the following compounds is used to decaffeinate coffee?