Which of the following statements are true about SRAM?

• A.  SRAM storage is based on the logic circuit known as a flip-flop.
• B.  A static RAM chip can store only about one-fourth as much data as a DRAM chip.
• C.  SRAMs are not usually reserved to use in caches.
• D.  Both [a] and [b]
• E.  None of these