Which two statements are true about extents? (Choose two.)

[answerhappygod]

Which two statements are true about extents? (Choose two.)

A. Blocks belonging to an extent can be spread across multiple data files.
B. Data blocks in an extent are logically contiguous but can be non-contiguous on disk.
C. The blocks of a newly allocated extent, although free, may have been used before.
D. Data blocks in an extent are automatically reclaimed for use by other objects in a tablespace when all the rows in a table are deleted.