Stefan would like his colleague Hossein to develop an exponential smoothing forecast with $=0\mathrm{.}333,$ but he knows that Hossein is familiar only with the moving average technique. In the interest of expediency, Stefan decides to tell Hossein to create a moving average forecast that has the same effect as exponential smoothing. How many periods should Stefan tell Hossein to use to approximate an exponential smoothing forecast with an $=0\mathrm{.}333?$

a$.3$

b$.4$

c$.5$

d$.6$