Detailed Answer
Answer (B) is correct.
Exponential smoothing is a widespread technique for making projections
because it requires less data be kept on hand than the moving average
methods. Mathematically, a forecast is arrived at with exponential
smoothing according to the following formula:
Forecast = (Smoothing factor × Previous month result) + (Smoothing factor complement × Previous month forecast)
= (0.3 × 158) + (0.7 × 148)
= 47.4 + 103.6
= 151