Calculate the mean absolute deviation $($MAD$)$ for the forecasts made by each technique in April through December. Which forecasting method do you prefer? $($Round your answer to $2$ decimal places$)$

a$)$ Exponential smoothing method $($alpha$=0\mathrm{.}30)(3\mathrm{.}58)$

b$)3-$month weighted moving average $(3\mathrm{.}58)$

c$)3-$month weighted moving average $(3\mathrm{.}99)$

d$)3-$month moving average $(4\mathrm{.}15)$