View the Exhibit. You want to create a tablespace to contain objects with block size 16 KB. But while configuring the storage you find that the block size that you can provide is only 8 KB. Which…

Extent allocation type (uniform vs. autoallocate) controls how extents are sized within a tablespace and has no relationship to the block size available for selection.

Segment Space Management (manual vs. automatic) governs how free and used space is tracked within segments using freelists or bitmaps, and does not influence the block size options.

Autoextension controls whether a data file grows automatically when space is exhausted; it has no effect on which block sizes are available for a tablespace.

Oracle supports multiple block sizes per database, but each non-default block size requires a dedicated buffer cache pool. Setting DB_16K_CACHE_SIZE to a nonzero value allocates a 16KB buffer cache, which is a prerequisite before any tablespace using a 16KB block size can be created. Without this parameter set, the Oracle instance has no memory pool to service 16KB block I/O, so the option is simply unavailable in the storage configuration UI.