Which of the Followings Statements Describes a Best Practice Regarding

Which of the followings statements describes a best practice regarding assurance engagement communication activities?

A) All assurance engagement observations should be communicated to the audit committee.
B) All assurance engagement observations should be included in the main section of the engagement communication.
C) During the "communicate" phase of an assurance engagement, it is best to define the methods and timing of engagement communications.
D) A detailed escalation process should be developed during the planning stage of an assurance engagement.