IPS efficiency is improved by: A) Compiling signatures into a decision tree to reduce comparison overhead; B) Using IPS sensors/filters to selectively apply signatures to relevant traffic, reducing unnecessary processing; D) Using a regular database instead of an extended one to lower memory usage. Option C's
"Turbo" and round-robin load balancing is not a standard Fortinet IPS feature. Option E is incorrect as C is not valid. Exact extract: "IPS efficiency is improved by compiling signatures into decision trees to minimize CPU usage... IPS sensors and filters allow selective signature application to reduce processing... Using the regular signature database instead of extended reduces memory footprint."