This year, a quarter of all new cars purchased in China will be an all-electric vehicle or a plug-in hybrid. There are roughly four million charging units in the country, double the number from a year ago, with more coming. While other E.V. markets are still heavily dependent on subsidies and financial incentives, China has entered a new phase: Consumers are weighing the merits of electric vehicles against gas-powered cars based on features and price without much consideration of state support. By comparison, the United States is far behind. This year, the country passed a key threshold of E.V.s accounting for 5 percent of new car sales. China passed that level in 2018. China has one of the fastest growing EV markets, with sales expected to double this year to about six million vehicles — more than the rest of the world combined.

Even new U.S. incentives have raised questions about how effective they will be in addressing mitigating factors for electric cars, such as long wait lists, limited supplies and high prices. The U.S. Inflation Reduction Act passed last month included a $7,500 tax credit for electric vehicles with conditions on where the cars are manufactured and where batteries are sourced. Automakers complained that the credit did not apply to many current E.V. models, and that the sourcing requirements could increase the cost of building an E.V.

It took China more than a decade of subsidies, long-term investments and infrastructure spending to lay the foundation for its electric vehicle market to start standing on its own. Some industry experts believe competition and dynamism are now driving the Chinese market, not government subsidies. The country’s seriousness about developing electric vehicles was on display when it rolled out the red carpet for Tesla to build a massive factory in Shanghai in 2018. The move was seen as a way to force the domestic market to compete directly with an industry leader.

From among the following options, choose the most appropriate synonym of “phase” with regard to its inherent meaning in the passage.