An operation analyst for forecasting this year's demand for one of his company's products based on the following historical data:

YEAR

Four years ago

Three years ago

Two years ago

Last year

QUANTITY SOLD

$10,000$

$12,000$

$18,000$

$20,000$

What is this year's forecast using exponential smoothing with alpha $=\mathrm{.}2,$ if last year's smoothed forecast was $15,000?$

a$.15,000$

b$.20,000$

c$.16,000$

d$.17,500$

e$.19,000$