On October 31st, 2015, the official Xinhua news agency reported that China would allow two children for every couple. That meant that the country's one-child policy came to an end. To control the population growth, China started a policy of one child per couple in the 1970s. Why does China decide to relax the policy now? In fact, China began relaxing the policy in January, 2014, allowing couples to have a second baby if the mother or father was an only child. The change was thought as a major liberalization   of the  family planning of over thirty years. But new figures   in January, 2015 suggested that fewer people than expected would like to have a second baby. Health officials said that there were about 11 million couples  under the new policy. However, only 1 million couples applied   to have a second child. Some couples said, "Two kids? Thanks but no." The influence of one-child policy seems hard to go in a short time. China's government has said that China will become the country with the most old people in the world in just 15 years, with more than 400 million people over the age of 60. And in the one-child families, when the only child grows up and gets married to another only child, they two have to take care of two old couples, the stress seems really heavy. To solve the problem of the _ population, one-child policy isn't suitable any more, and two-child policy is needed and necessary. According to the passage, we know that   _  .
China started one-child policy in the 1980s two-child policy isn't suitable any more now China will have the most old people in the world in just 15 years China will have less than 400 million people over the age of 60 in 15 years