I will agree with you on B and C. Not so much on A. Not saying A isn't true, just that it isn't as simple as most people think. And probably is impossible to prove due to all the unknown side effects. An example of a side effect not related to veganism is the effect monocrop farming has on bees. Noone saw that coming until it happened. So changes to what is planted and such to support veganism could turn out to be less sustainable for reasons we can't fathom. Similar on the "better for the planet". We can't really know that. So I wouldn't put that under "litterally" right. Just probably right. In general I think diversity is better than one thing or the other. In the US the balance is way over toward the animal side. Shifting toward less of that would for sure be good. But going all the way to no animal products will probably have it's own issues on things.