An administrator wants to test the performance of an application at different memory sizes.  What is the most effective way to perform the test and collect statistical information for each test？（）  

• A、Run DLPAR to change the LPAR memory for each test.
• B、Run rmss command to simulate different memory for each test.
• C、Run chdev command to limit the system memory size for each test.
• D、Run chattr command to limit the system memory size for each test.