In a single-tier environment running WebSphere Commerce V5.6 Professional Edition， traffic has increased significantly over the last month.  It has been determined that load has increased throughout the system. Which is the BEST change to provide the largest increase in performance？（）

• A、Upgrade to WebSphere Commerce V5.6 Business Edition
• B、Create a two-tier environment by moving the database server to a new node
• C、Create a demilitarized zone （DMZ） between two firewalls
• D、Compile all the store JPSs
• E、Disable all caching of JSPs