Which of the items below should be considered when scheduling an engagement. 1. Availability of key process personnel. 2. Availability of external auditors. 3. Availability of engagement resources. 4. Availability of outside resources. 5. Availability of key reviewers. 1,3,4,5 1,3,5 1,2,3,4,5 1,2,3,4 1,2,4,5