About limit user trace???

In which two ways can a DBA limit the size of the user trace files? (Choose two)

A. Set the MAX_DUMP_FILE initSID.ora file
B. Set the MAX_DUMP_FILE_SIZE in the initSID.ora file
C. Initiate the ALTER SESSION TRUNCATE TRACE TO integer KIM command
D. Initiate the ALTER SYSTEM SET MAX_IGMP_FILE_SIZE=integer command

B is one choice surely, but how about the other one??? Mess me, I have seeked the answer in all documentations.

Only B is a possible answer. Wher do you get those questions from?

A friend sent it to me. Actually it really messed me.