What is the primary purpose of the 'Manage by exception' principle?
Delegating authority within agreed tolerances is precisely what 'manage by exception' enables: the Project Board sets tolerances for time, cost, scope, quality, risk and benefit, then only intervenes when the Project Manager forecasts a breach. This satisfies the stem's focus on the principle's primary purpose — escalation by exception rather than routine reporting.
Why this answer
Manage by exception means that the Project Board only needs to be involved when tolerances are forecast to be exceeded. This frees them to focus on strategic decisions.