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

Answer options:

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.

BC