The best reagent top concert pent -3-en-2-ol into pent 3-en2-one is

Question

$\begin{array}{1 1} Acidic \;per magnate \\ Acidic \;dichromate \\ Chromic \;anhydride\;in\;glxical \;acetic\; acid \\ \text{Pyridium chloro-chromate } \end{array} $