<prompt> Obstruction in pulmonary stenosis may occur at the following sites:SupravalvularValvularSubvalvularAll of the above  <response>: d. All of the aboveRef: Nelsons 20e p 2211-2217, Ghai 8e p 420-423Pulmonary stenosis can occur due to obstruction at supravalvular, valvular or subvalvular level. 