There never was such an option -- are you referring to the "force video to sync to audio time"? That was renamed, it's still there, but it was never meant for webcam sync. You can use the "mic time offset (milliseconds)" in audio settings to adjust mic playback timing as a way to force the mic to sync to the webcam is to use.
Another option to force webcam sync is to disable your microphone in audio settings, then go into the webcam device source properties (right click->properties or double click on it) and set the audio device directly there to your microphone. After that, turn on "Use buffering" and it should force it to stay in sync.
