Final answer:
To upgrade your system with the fastest memory, choose the memory that is supported by your motherboard, which might be DDR4 if it is compatible, but always verify what your system can support.
Therefore, the correct answer is: option D. memory that is supported by your motherboard.
Step-by-step explanation:
If you're looking to upgrade all the memory in your system with the fastest memory available, the best choice would be the type of memory that is supported by your motherboard.
While options like DDR4 are typically faster than DDR3 or DDR2—since DDR4 is the newest standard among those listed—it won't benefit you if it's not compatible with your system.
Always consult your system's specifications or motherboard manual to determine which type of memory is supported.
If your motherboard supports DDR4, then that would be your fastest option. However, the compatibility is crucial, and not all systems will support the latest standards.