Automatic space reclamation for column-organized tables can be accomplished in which of the following
scenarios?

A.
When the registry variable DB2_AUTORECLAIMSPACE=YES

B.
After termination all the back-end processes using TERMINATE command

C.
After setting the database configuration parameter AUTO_DEL_REC_OBJ to ON

D.
When the registry variable DB2_WORKLOAD=ANALYTICS prior to database creation

Explanation:
https://www.ibm.com/support/knowledgecenter/SSEPGG_11.1.0/com.ibm.db2.luw.admin.perf.doc/
doc/c0061069.html