Deng xiaoping believed that the standard of living in china could be improved by reducing population growth increasing population growth allowing farmers to have large families moving people from the crowded eastern coast

Correct  reducing population growth

Deng Xiaoping rose to power in China in the years following the death of Mao Zedong in 1976.  Mao had opposed the idea of controlling population growth in China, saying, "The more people there are, the stronger we are."  But Deng started a new policy in China in 1979, the "one child policy."  Under the policy, most Chinese families were restricted to having only one child. Incentives for jobs and financial advantage were in place for those who complied with the policy, and sometimes harsh measures such as sterilizations and abortions were implemented during the years that the policy remained in force.

When originally begun by Deng, the one-child policy had the goal of restricting population growth so that it did not go faster than China's  economic development was able to support.

the underground railroad (apocope of the metropolitan railroad) is a system of urban trains located within a city and its metropolitan area. it is characterized for being a massive transport of passengers in the big cities, uniting diverse zones and their environs, with high capacity and frequency and in segregated form to other systems of transport. metropolitan railroads are built underground or on the surface, although most systems use mixed models where sections are combined in both modalities.

1 - as a result, the metro tends to reduce car travel for two reasons: first, due to the greater transfer of users from the car and, second, due to the reduction in the acquisition of cars in homes located in sectors near the stations of the metro.

2 -the metro allows to contribute effectively to the achievement of all the objectives of an urban development policy: it improves the efficiency of the city's economy by reducing travel costs and also generates a higher level of activities in the city center, taking advantage of of the agglomeration economies.

3 -it is a clean means of transport, since it uses renewable energy (usually electricity), taking care of the environment and avoiding excessive pollution.