Which three are true about the default database buffer cache? (Choose three.)

Oracle uses an enhanced Least Recently Used (LRU) algorithm for buffer reuse, which considers factors beyond simple recency, not based solely on LRU.

The database buffer cache is a primary and essential component within the System Global Area (SGA), which is allocated as a contiguous and relatively fixed block of memory at instance startup.

Oracle's buffer replacement algorithm is an enhanced LRU, not solely a touch count algorithm, as it considers multiple factors for buffer reuse.

The default buffer cache primarily stores blocks corresponding to the `DB_BLOCK_SIZE`; blocks from tablespaces with non-default block sizes reside in their specific `DB_nK_CACHE` pools.

While configured separately, the `KEEP` and `RECYCLE` buffer pools functionally manage subsets of blocks that would otherwise reside in the default buffer cache, representing specialized management strategies within the overall buffer memory.

When a data block is modified in the buffer cache, its in-memory 'dirty' image is different from the image currently on disk, meaning the specific buffer image does not yet have an exact corresponding image in the data file until it is written.