Which two statements correctly describe the relation between a data file and the logical database structures? (Choose two)

An extent is a contiguous set of Oracle data blocks allocated within a single data file; it cannot straddle two data files because block addresses are file-relative and contiguous allocation is enforced per-file.

A segment can span multiple data files as long as all those files belong to the same tablespace; each individual extent within the segment is confined to one file, but the segment as a whole is not restricted to a single file.

A data file is permanently associated with exactly one tablespace at creation time and cannot be shared between or reassigned to another tablespace without being re-created.

A single data file can hold extents from many different segments - tables, indexes, LOBs, and others - so this statement is false.

A data block is the smallest unit of I/O in Oracle and is entirely contained within a single data file; it cannot span OS blocks from different files.