The correct answers are B. Boundaries of the OHSMS and C. Processes and functions.
In audit terminology, the audit scope describes the extent and boundaries of the audit. This includes matters such as the physical locations, organizational units, activities, processes, and functions being audited. In ISO 45001, the organization is also required to determine the boundaries and applicability of its OH and S management system when establishing its scope under Clause 4.3. Therefore, the boundaries of the OHSMS and the relevant processes and functions are part of audit scope.
Why the other options are not part of the audit scope:
A. Trade union communications may be relevant audit evidence or an issue within worker participation and consultation, but it is not itself a standard way to define the audit scope.
D. Audit checklists are audit preparation tools, not part of the scope.
E. Organisation procedures are usually part of the audit criteria, because auditors compare actual practice against documented procedures.
F. ISO 45001 requirements are also part of the audit criteria, since they are the requirements against which conformity is assessed.
So, the two issues that are part of the audit scope are:
B, C
