Which of the Following Statements About Vendor Analysis Is True

Which of the following statements about vendor analysis is true?

A) Vendor analysis can be done both before and after purchases to compare performance on evaluation criteria and evaluate the process of vendor selection.
B) A vendor analysis is often ineffective since it makes the purchasing process extremely complex.
C) Organizational buyers primarily use a vendor analysis to evaluate possible marketers of the organization's products.
D) Vendor analysis should be done only during the postpurchase evaluation stage of the organizational buying process.