Out of the choices given, assuming it's a 1-on-1 fight, probably BJJ. It's the only discipline where you can control how much or how little you want to hurt the person. You can simply hold them or go so far as killing them with many of the same techniques. Obviously, you are taking someone to the ground, and against multiple people this isn't a great idea. I would contend however, that no art or fighting style is great against multiple opponents. The best ides there is to run and ideally have a blade or a firearm. Boxing would be very useful against multiple attackers if you needed to engage.
I've done martial arts for 24 years (BJJ for the past 14 years, Wrestling for the past 5 years, Judo for 4 years in the 00's, boxing and Muay Thai for the past 3 years. Prior to those I was doing TMAs) and most of what people teach for
"self defense" is garbage. Any style where you can compete is going to give you a massive edge because prepping for a fight or competitive situation and then going in and doing the thing against someone that isn't concerned about your safety is going to help prep you way better than learning some "self-defense based art" like Krav Maga.
Basically my thoughts on self defense (Time-coded to start and lasts 3 mins and 10 seconds)
Boxing cause it's good against more opponents, hit and run, in and out.
wrestling and grappling are cool but really you have to be occupied with only one person for those and if the friends of the opponent decide to join in you stuck in there with more people on you who will overwhelm you so it's a wrap.
That's absolutely a concern re: grappling, but I've always liked that you get to choose what level of damage or control you inflict. Obviously these types of cases are incredibly rare but an MMA guy with a boxing base in my city got jumped at a barn punched a guy in the eye, the guy's orbital bone broke into his eyeball and blinded him, and the guy that got jumped is now in prison serving some years for maiming and assault with intent to inflict serious bodily harm. Again, you gotta protect yourself first and worry about the law later, but it's a fukked up situation.
I think if someone is serious about self defense they need to be not looking down at their phone, keep good posture, don't fumble for your keys at your car or home door, don't look like a victim, be good at verbal de-escalation, be looking for where the are exits in buildings, sit facing the front door whenever possible in public, carry a gun or a blade and train with it, and be mentally and spiritually prepared to hurt or possibly kill someone if your life or the life of a loved one is in danger. And even then it may not be enough. Sometimes you're just gonna end up fukked. But preparing mentally and physically for those things are way more important for self defense IMHO than a single fighting discipline, because they all have weaknesses.
