get value of rediobuttonlist control

I am finding all the radiobuttonlist on a placeholder -- how do i find the selected value of each of them

foreach (WebControl RadioList in PHRadio.Controls)
      { 
      
       if (RadioList is RadioButtonList)
       {

how do i get the the radiolist.selectedvalue

I get 'System.Web.UI.WebControls.WebControl' does not contain a definition for 'SelectedValue'

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