China's auto manufacturers are developing smart cars. The direct reason is that gasoline prices are rising. Consumers' awareness of energy saving is constantly increasing, and the development of energy-saving cars requires a large amount of investment. China FAW Group will invest in energy-saving cars by 2015. Invest 13 billion yuan in development costs for self-owned brand cars. Shanghai Automobile Group also plans to invest 21.4 billion yuan in 2012 for the development of energy-saving technologies for new vehicles and the development and competition of energy-saving vehicles, which is expected to accelerate the adjustment of the Chinese automobile industry. To improve the chaotic situation of large and small enterprises. Which of the following is most likely the reason why Chinese automakers invest in energy-efficient cars? ['Energy-saving cars are not yet widespread in China.', 'Huge market prospects for energy-efficient cars.', 'Development of energy-efficient vehicles requires a huge investment.', 'Energy-saving cars are the development trend of the automotive industry.']