According to IIA guidance, during the development of an internal audit charter, which is true...

Both the board and senior management should provide input during development of the internal audit charter because the charter establishes internal audit’s mandate, organizational position, authority, responsibilities, reporting relationships, and scope of services. The CAE typically develops or maintains the charter through discussion with these key stakeholders. Board involvement is essential because the board provides functional oversight and ultimately approves the charter. Senior management input is also appropriate because management must understand internal audit’s role, cooperate with its activities, and recognize its authorized access and responsibilities. Legal counsel may contribute where relevant, but it is not the only party besides the board permitted to participate. Nor must board input be restricted solely to an audit committee. The Internal Audit Fundamentals material likewise describes the charter as approved by the governing body and agreed to by senior management.