You are shrinking the SCOTT.EMP table by executing the ALTER TABLE SCOTT.EMP SHRINK SPACE CASCADE statement. What is a prerequisite for shrinking the SCOTT.EMP table？（） A: You must enable the block change tracking feature. B: You must have enable the flashback feature. C: You must use the OMF in your database. D: You must define the tablespace of the SCOTEMP table for automatic segment space management.