Option C. Sleek and modern looking, but also low-profile. With many TVs having short bases, it's important that it does not block the screen, but it is equally important that it looks good sitting on your entertainment center.
As for features, HDMI-ARC is the biggest one for me. Most TVs support it now and it allows for the best audio quality, easiest setup (plug and play, usually with no remote pairing needed), and is the most flexible and future-proof. As long as the sound bar has HDMI-ARC and good sound, everything else is gravy. Stuff like voice control is always a nice bonus, but ultimately I rely on my Google Home connected to my Chromecast to handle that functionality.