Pre-defined Scan Task For Rootkits
Since the Rootkit Scan is a system-wide scan, Bitdefender shouldn't ask to add target for Rootkit Scan. It is a wastage of time, I think, because first it scan all files and then for Rootkits probably.
I know that Rootkit always infect the system partition or the MBR and most Rootkits are dropped by Trojans. So re-design the scanning method that also scan for Trojans etc instead of asking Scan Targets e.g separate pre-defined Scan Task for Rootkits only.