Which two statements are true regarding transactions in an Oracle database? (Choose two.)

Multiple transactions can reside in the same undo segment simultaneously - Oracle uses a transaction table in the undo segment header to track each transaction's undo entries separately, allowing concurrent sharing of the same segment.

When a transaction issues its first DML statement, Oracle assigns it to an undo segment in the undo tablespace, where all before-image data for that transaction is stored until it commits or rolls back.

Multiple transactions can and do share the same undo segment and its extents - each transaction is differentiated by a separate slot in the segment's transaction table, not by exclusive extent ownership.

Oracle does not fall back to the system undo segment for user transactions when the undo tablespace is full; instead the transaction receives an ORA-30036 error indicating the undo tablespace cannot extend.