During the course of an audit, an auditor required additional research and consultation with others. This additional research and consultation is considered to be

A.	A responsibility of the management, not the auditor.
B.	An appropriate part of the professional conduct of the engagement.
C.	An unusual practice indicating that the CPA should not have accepted the engagement.
D.	A failure on the part of the CPA to comply with GAAS because of a lack of competence.