How should the DB_FLASH_CACHE_SIZE be configured to use both devices?

You have installed two 64G flash devices to support the Database Smart Flash Cache
feature on your database server that is running on Oracle Linux. You have set the
DB_SMART_FLASH_FILE parameter: DB_FLASH_CACHE_FILE= ‘/dev/flash_device_1 ‘,’
/dev/flash_device_2’ How should the DB_FLASH_CACHE_SIZE be configured to use both
devices?

A.
Set DB_FLASH_CACHE_ZISE = 64G.

B.
Set DB_FLASH_CACHE_ZISE = 64G, 64G

C.
Set DB_FLASH_CACHE_ZISE = 128G.

D.
DB_FLASH_CACHE_SIZE is automatically configured by the instance at startup.