请问以下题目的答案是什么?
Which two statements about row migration are true? (Choose two.)
A. Row migration is caused by a PCTFREE value set too low
B. Row migration can be resolved using the ANALYZE command.
C. Row migration can be reduced by choosing a larger block size.
D. Row migration means that row pieces are stored in different blocks.
E. Queries that use an index to select migrated rows perform additional I/O.
答案：
