The owner of Darkest Tans Unlimited in a local mall is forecasting this month's (October's) demand for the one new tanning booth based on the following historical data:

col1 Month April May June July August September
col2 Number of Visits 100 140 110 150 120 160

What is this month's forecast using a four-month weighted moving average with weights of .4. .3.2, and .1?

a. 135
b. 120
c. 129
d. 140
e. 141