Which three statements are true about undo segments and the use of undo by transactions in an Oracle

Which three statements are true about undo segments and the use of undo by transactions in an Oracle database instance? (Choose three.)

A. Undo segments have a minimum of three extents

B. Undo segments can wrap around to the first extent when a transaction fills the last extend of the undo segment

C. Undo segments must be stored in a SMALLFILE tablespace

D. Undo segments can extend when a transaction fills the last extent of the undo segment

E. An undo segment may be used by multiple transactions simultaneously

F. Undo segments must be stored in a BIGFILE tablespace

G. A single transaction may use multiple undo segments simultaneously

Correct Answer: C,D,E