Hi, Brad. Best of luck on your first deal! I would recommend networking and using the "D" method as you have stated below. Below are a few thought to why I think this might be best:
A. You can absolutely invest in syndication, but if you want to hand it down to the kids/grandkids, this will look a little different because you won't own/control the actual asset.
B + C. Everybody wants a turnkey property that has good cash flow and equity appreciation. You could do this yes, but it is harder to scale (in my opinion). I also don't always trust the face value of the analytics for turnkey properties, make sure you run the numbers yourself!
D. Building a team in the long run is so important. Not to mention if you are able to "manually" find a property and build a team around you to manage your portfolio and grow. Also the best deals will be the ones you go out and find yourself whether it be wholesalers, off market, or other. In addition, I always trust my own analysis anyways compared to the numbers of what some "turn key" properties may boast.
In general, real estate can be as passive or as manual as you would like. I personally like to be hands-on in my investments and learn the ropes through analytics, property management, and deal finding. This is just my 2 cents!