Which of the following statement(s) is a correct comparison of the two sales forecasting approaches?

a. Sales force forecasting requires more aggregate data about sales than trend analysis.

b. Unlike trend analysis, sales force forecasting is a survey-based approach.

c. Both trend analysis and sales force forecasting can be enhanced by the Delphi technique.

d. Neither trend analysis nor sales force forecasting utilizes the Delphi technique.

e. Unlike sales force forecasting, trend analysis cannot be applied unless the firm has collected aggregate sales data over many years.