The Delphi Method of Forecasting Is Useful When

The Delphi method of forecasting is useful when

A) historical data is available and the best basis for making projections is to use past demand patterns.
B) a systematic approach to creating and testing hypotheses is needed and the data are usually gathered by sending a questionnaire to consumers.
C) judgment and opinion are the only bases for making informed projections.
D) historical data are available and the relationship between the factor to be forecast and other external or internal factors can be identified.