How does the moving average technique determine a next-period forecast?

	a.	By averaging a certain number of the most recent data to generate a forecast.
	b.	By calculating a weighted average of n-period observations using varied weights.
	c.	By identifying a causal variable, which is a predictor of demand, and using linear regression to identify the forecast equation.
	d.	By using the current periods forecast, adjusted by a weighted difference between the current periods actual data and the forecast.
	e.	By assuming that the introduction and growth pattern of a new service will mimic the pattern of a similar concept for which data are available.