Which is the most suitable reagent for the following conversion ? $CH_3-CH=CH-CH_2-C-CH_3 \to CH_3-CH =CH-CH_2-c -OH$

Question

$\begin{array}{1 1} tollen's \;reagent \\ Benzoyl \;peroxide \\ I_2\;and\;NaOH\;solution \\ S_n and \;NaOH\;solution \end{array} $