One of the users in the PROD database，Adams，complains that his update on the table，TRANS， is taking an unusually long time to complete. You find that the table gets locked by another database user before Adams starts his transactions，and you are unable to contact the user holding the table lock. As Adams is updating some crucial rows in the table， he should get the highest priority. Which method would you use to overcome this problem？（）

A. execute the command， ALTER SESSION KIL.， to kill the blocking session
B. execute the DBMS_SESSIOKILL_SESSION procedure to kill the blocking session
C. execute the command， ALTER SYSTEM KILL SESSIO.， to kill the blocking session
D. execute the command， ALTER SESSION UNLOC.， to release the lock for the blocking session
E. execute the command， ALTER SYSTEM UNLOCK SESSIO.， to release the lock for the blocking sessio