What could be the reason for this?

You specified the warning and critical thresholds for a locally managed tablespace to be 60% and 70%, respectively.
From the tablespace space usage metrics, you find that the space usage has reached the specified warning threshold value, but no alerts have been generated.
What could be the reason for this?

A.
The event parameter was not set.

B.
The sql_trace parameter is set to false.

C.
Enterprise Manager was not used.

D.
The statistics_level parameter is set to basic.

E.
The t:kid_statistics parameter is set to false.