Which three statements are true about logical structures of the Oracle database?

Which three statements are true about logical structures of the Oracle database? (Choose
three.)

A.
Each segment contains one or more extents.

B.
Multipletablespaces can share a single data file.

C.
A data block is the smallest unit of input/output (I/O) in data files.

D.
It is possible to havetablespaces of different block sizes in a database.

E.
Each data block in the database always corresponds to one operating system
block.