There is a lot of ways that you can use the bit locker encryption. Some are when you are authenticating your computer using a TPM. Or when you are authenticating your account using a USB Flash drive, and most on the phones authentication through text messages and all.
The correct answer would be Windows.
SRAM [STATIC] is a type of memory, it is five times faster than DRAM [which is found in most computers] and it depends on the use of electricity. It is designed in such a way that its constant refreshing is not require, it is much more expensive than the DRAM and it is therefore only used in cache memory application.<span />