Which Discipline in 8D Methodology describes the action of the Network Administrator?

A Network Administrator of a company has been made aware of a problem with the telephone system, and contacts a few colleagues who have dealt with similar problems in the past.

Which Discipline in 8D Methodology describes the action of the Network Administrator?
A . D4
B . D3
C . D2
D . D1

Answer: A

Explanation:

Reference: http://www.brooks.com/my-brooks/suppliers/~/media/Files/Suppliers/Documents/5_Why_Root_Cause_Corrective_Actions.pdf