Which of the Following Methods for Achieving Coordination in a Supply

Which of the following methods for achieving coordination in a supply chain would be considered an "informal approach" to achieving coordination?

A) Customer account teams to provide a single point of contact.
B) Establishing corporate-level SCM-oriented councils to implement best practices.
C) Establishing teams that include multiple functions and processes to develop supply chain strategies and tactics.
D) Global supply teams to manage the suppliers.
E) Use of social media networks.