The correct answer is B) gender imbalance.
The demographic shift that has resulted from China’s one-child policy is gender imbalance.
Originally, the intention of the one-child policy was to reduce the population growth in that populated country. Some people say it reduces population in 300 million in twenty years, but the policy also carried another consequences that were not foreseen by the government such as gender imbalance. After those years, males babies have outnumbered females babies. The sex ratio was 1.7 in 2001. The sex ratio at birth is the proportion of boys live births to girls live births.