For a Salesperson Trying to Determine the Impact of Group

For a salesperson trying to determine the impact of group forces on the organizational buying process,which of the following questions are appropriate?

A) Which organizational members take part in the buying process?
B) What is each member's relative influence in the decision?
C) What criteria are important to each member in evaluating prospective suppliers?
D) All of the above questions are appropriate.
E) Only (a) and (b) are appropriate.