You can Terminate and Quarantine applications in D+ > View Active Process List.
If you're talking about having this option in the D+ alert pop-ups, I don't think it would be necessary because D+ will alert you BEFORE the application is even loaded into memory, so it wouldn't need to be 'Killed', only blocked.
No No No.... i mean it would be good cuz if its malware well have to just click one option 'kill process' to block it instead of clicking 2 or 3 such as 'deny elevated privilege', 'modify program access to protected folders' etc. itll reduce no of popups if we dont want the app to run at all...