You need to collect and aggregate statistics for the ACCTG service and PAYROLL module, and...

When you enable statistics gathering for a specific service and module using DBMS_MONITOR.SERV_MOD_ACT_STAT_ENABLE, the output is aggregated and can be viewed using the V$SERV_MOD_ACT_STATS dynamic performance view. This view contains the cumulative statistics of database activity broken down by service and module, which is exactly what you collect when executing the provided command.

B (Incorrect): While many types of trace files are located in the Diagnostic Destination directory ($ORACLE_BASE/diag), the aggregated statistics for services and modules are not written to trace files but are instead viewable through dynamic performance views.

C (Incorrect): The V$SERVICE_STATS view provides service-level statistics but does not provide the combined service/module-level breakdown.

D (Incorrect): The output of the PL/SQL block is not written to a file in the current working directory; it is stored in the data dictionary and accessible via dynamic performance views.

References:

Oracle Database PL/SQL Packages and Types Reference: DBMS_MONITOR

Oracle Database Reference: V$SERV_MOD_ACT_STATS