Selected Answer: B Caches and Registers - Data in memory is the most volatile. This includes data in central processor unit (CPU) registers, caches, and system random access memory (RAM). - Data in cache and CPU registers is the most volatile, mainly because the storage space is so small. https://blogs.getcertifiedgetahead.com/cfr-and-order-of-volatility/#:~:text=Caches%20and%20Registers,storage%20space%20is%20so%20small.