Using the data set below, what would be the forecast for period $5$ using the exponential smoothing method? Assume the forecast for period $4$ is $14000.$ Use a smoothing constant of $=0\mathrm{.}4($Choose the closest answer.$)$

$\backslash$table$[[$Period$,$Actual Demand$],[1,10,000],[2,12,400],[3,13,250],[4,14,750],[5,15,220],[6,18,500]]$

a$.14,030$

b$.13,190$

c$.15,220$

d$.12,660$