Various types of proof can be used to maintain an assurance case for the operational assurance process includes: Select one: a. All of the choices b. A set of organization sanctioned actions, procedures, or protocols that can be invoked when an anticipated threat occurs has been established c. A process is in place to ensure that the Business Continuity Plan is kept up to date. d. An organizationally standard procedure manual is in place, which details the steps for every activity in the operational assurance process