Which of the Following Methods May Be Used to Smooth

Multiple Choice

Which of the following methods may be used to smooth a time series sufficiently to remove the random variation and to discover the existence of the other time-series components?

A) Moving averages and exponential smoothing.
B) Exponential smoothing and deseasonalising.
C) Deseasonalising and mean absolute deviation.
D) Mean absolute deviation and the percentage of trend.