The correct answer is: A. Use of metering system.
A metering system is a system that measures the amount of water that is used. This can be done by using a water meter, which is a device that measures the volume of water that flows through it. Metering systems can be used to track water usage in homes, businesses, and other facilities.
There are several reasons why metering systems can lead to a decrease in per capita consumption. First, metering systems can help people to be more aware of their water usage. When people know how much water they are using, they are more likely to take steps to conserve water. Second, metering systems can make it more expensive to use water. This can also encourage people to conserve water. Third, metering systems can help to identify leaks in water systems. Leaks can waste a lot of water, so identifying and fixing them can help to reduce water usage.
The other options are not as likely to lead to a decrease in per capita consumption. Good quality of water is important for public health, but it is not likely to have a significant impact on water usage. Better standard of living can lead to increased water usage, as people have more money to spend on things like water-intensive activities such as swimming and gardening. Hotter climate can lead to increased water usage, as people need to use more water for things like cooling and irrigation.