Q:Read the following article and select the best answer. Article: China is the country with the largest population in the world. Too many people cause many problems such as food problem. And today, China's population is still growing very fast. So in order to control the population, China has formulated the policy of family planning, that is late marriage, late childbirth and having fewer but healthier children. Men of 22 years old and women of 20 years can get married. If a man of 25 or over 25 gets married with a wo-man of 23 or over 23 , their marriage is late marriage. Childbirth by a woman at the age of 23 or late is a late childbirth. The country encourages people to have only one child. Family planning is a useful policy to control China's population. And it is still needed in China in the following years. Question: What is the passage about? - China's population - China's family planning - China's late marriage - China's childbirth
A:
China's family planning