Generally, the closer the date, the more accurate the prediction. I say part A is true (unless China supresses the RMB) and part C is a shot in the dark.
If China surpassed the US in nominal GDP, it would be the undisputed largest economy. PPP is for the domestic economy; nominal is for international trade. Every healthy economy is majority (>70%) domestic. So PPP is about a couple times more important than nominal. In China's case, it's about 3X. China is already truly the largest economy.
China's GDP is tech and manufacturing; American GDP is education debt, interest fees, healthcare bills and litigation costs. A ingot of steel vs a brick of mud and hay with gold spray paint.
Very wrong to say the US just education debt, interest fees and brick of mud. Seriously sometimes i feel like some people on this forum act like indians towards countries they dont like. Lol. Reminds me of those anti china people whonclaim chinas economy is only low cost forced slave labour, copy cat, cheap goods, building empty ghost cities to add to GDP etc etc. Lol
We shouldn't go to that level. To say US economy is just brick mud and interests fees is just so ridiculous, since if that was the case, China wont even need to worry at all about the US and they could easily handle the US without breaking a sweat. This of course is totally false. People should remain humble and be rational/pragmatic like Chinese leaders. If most Chinese people/leaders start having the mentality i see on some people here of underestimating others and thinking they are at the top and better than everyone else , then that will be the day their decline will actually start. I didnt even expect to see such thibking this early when china is still in her development stage . At least become the undisputed number one globally before start making such remarks.
I guess we shouldn't be surprised why they say every superpower/reigning empire last about 250 years more or less on average bedore the rot and decline sets in, which makes sense as thats the time it takes for those who suffered hardships to build the country/system before their grand kids(and subsequent generation) generation who grew up only knowing in abundance take over and the arrogance/complacency starts setting in. Its only human i guess.