Which is the correct description of database time?

You analyze an Automatic Database Diagnostic Monitor (ADDM) report to identify the component that contributes most to the database time.
Which is the correct description of database time?

A.
It is the sum of the CPU time of all nonidle sessions.

B.
It is the sum of wait time and the CPU time of all nonidle sessions.

C.
It is the time spent in processing the input/output (I/O) request by users.

D.
It is the difference between the wait time and the CPU time of all nonidle sessions.