Concerning the Eight-Stage Model of the Organizational Buying Process, Research

Concerning the eight-stage model of the organizational buying process, research suggests that:

A) the process may be reoriented at any point by a redefinition of the basic problem.
B) the process may be discontinued by a change in the external environment.
C) certain stages may be completed concurrently.
D) many small or incremental decisions are made during the procurement process that ultimately translate into the final selection of a supplier.
E) all of the answer choices