The fee standards for public utilities should try to ensure that the government does not subsidize or make more money. However, due to the lack of a competitive market, this is difficult to achieve. There are some public utilities with a service nature, or in order to take care of the low-income class, the fees are lower. It is even free and the cost is borne by all taxpayers. What is the correct understanding of the above text? ['Utility charges can be adjusted by the market.', 'Utilities should implement free services for the general public.', 'Low-income classes need care from all aspects of society.', 'Public utilities must be funded by the government.']