4. (2 points) In a server, the processor accounts for 50% of total server power, the memory system accounts for 30%, the disk accounts for 10%, and miscellaneous components account for the remaining 10%. You have a $500 budget to upgrade your server to make it more power-efficient. You plan to either replace your memory module with a new memory module or your disk with a new disk. With that budget, you can either purchase a new memory module that consumes 20% less power than your old memory module, or a new disk that consumes 40% less power than your old disk. Which of the two will you purchase if you were only concerned with reducing your server's power consumption