To provide efficient roaming between the cells， which percent of cell overlap is recommended for2.4 GHz and 5 GHz access points？（）

• A、5 to 10 percent for both 2.4 GHz and 5 GHz
• B、10 percent for both 2.4 GHz and 5 GHz
• C、20 percent for 2.4 GHz and 15 to 20 percent for 5 GHz
• D、20 percent for 2.5 GHz and 10 percent for 5 GHz