Examine the following PL/SQL block：  
SET SERVEROUTPUT ON SET LONG 10000 ECLARE report clob； 
BEGIN report ：= DBMS_SPM.EVOLVE_SQL_PLAN_BASELINE（）；
DBMS_OUTPUT.PUT_LINE（report）；
END；  
Which statement describes the effect of the execution of the above PL/SQL block？（）  

A. The plan baselines are verified with the SQL profiles.
B. All fixed plan baselines are converted into nonfixed plan baselines.
C. All the nonaccepted SQL profiles are accepted into the plan baseline.
D. The nonaccepted plans in the SQL Management Base are verified with the existing plan baselines.