China's announcement in early September that it planned to set a date to end sales of new vehicles with combustion engines should have rocked the global auto industry.

The world's largest car market, at roughly 30 million vehicles a year, will at some point permit only zero-emission vehicles to be sold.

That will accelerate the development, production, and sale of battery-electric cars around the world—whether automakers want to or not.

DON'T MISS: China developing timetable to end sales, production of gasoline cars

We don't yet know when that will be, and the year is likely to be 10 to 20 years hence, to ensure China doesn't appreciably hurt its domestic auto industry.

Still, major Western carmakers are planning to increase their efforts in electric cars.

GM has declared, "The future is electric," with two more battery-electric models planned by 2020, and the Renault Nissan Mitsubishi combines plans multiple electric vehicles on shared platforms starting around the same year.

So we were curious to poll our Twitter followers to see where they felt electric cars would penetrate most strongly by, say, 2025.

Each of the options could reasonably be deemed the one where EVs will have the greatest market share just seven years hence.

READ THIS: Is China making U.S. irrelevant to the future of automobiles?

China already buys more cars with plugs than any other world market, and sales have surged under a combination of carrots and sticks for car buyers at both the national and local levels.

Europe is extremely serious about reducing vehicular carbon-dioxide emissions that contribute to climate change, especially in the wake of the Volkswagen diesel scandals and greater public awareness of the general lack of emission compliance among most diesel cars.

Oslo street scene: Nissan Leaf, Volkswagen e-Golf, Tesla Model S, July 2015

Oslo street scene: Nissan Leaf, Volkswagen e-Golf, Tesla Model S, July 2015

Then there's Japan, which has long given favorable tax treatment to hybrids, and whose hometown maker Nissan has built the highest-volume electric car ever, the Leaf that's now going into its second generation.

Finally, there's North America, where buyers in some regions prize cars with new and advanced technology and where global auto trends have often taken root. (Think SUVs.)

CHECK OUT: When will U.S. ban sales of new cars with engines? Poll results

We're curious to see whether our followers feel China is the obvious leader here or whether other markets may actually go first in buying a higher percentage of plug-in electric cars—so go ahead and cast your vote.

As always, please note that our Twitter polls are far from scientifically valid, due to small sample size and self-selection by those who choose to participate.

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