See the Exhibit: 

You enabled the PL/SQL tracing in a user session using the following command: 

Examine the output. After some time, the query procedures a different result. What is the cause for the change? 

Answer options:

A. The FOO procedure has been executed more than once
B. The PLSQL_DEBUG parameter is set to FALSE for the user session
C. The FOO procedure has been compiled with the DEBUG option and executed
D. Schema level statistics have been gathered by the database administrator

C