Hint: It is celebrated to raise awareness about the impact of a growing population and issues such as gender equality, family planning, maternal health, human rights, etc.
Events are celebrated globally to mark an occasion or to raise awareness related to a particular issue. International events are occasions for educating the public on matters of concern, to address global issues, and celebrating and strengthening achievements.
A) World Population Day is an event that is observed every year on July 11. It is aimed at raising awareness of global population issues. The event was established in 1989 by the UN Development Programme's Governing Council.
B) World No Tobacco Day is celebrated around the globe on May 31 each year. This annual celebration educates the public about the dangers of tobacco use on health.
C) World Environment Day is celebrated on June 5 every year. It is marked by planting trees, conservation efforts, and other environment related activities. It is celebrated to highlight the environmental issues faced by the world. It aims to create awareness on the need to protect and safeguard the environment by practicing environment safety measures.
D) World Health Day is celebrated on the 7th of April every year. The celebration is aimed at raising awareness of a particular health theme. The celebration is marked by activities which serve as an opportunity to focus on important aspects of global health worldwide.
Hence the correct answer is option ‘A’.
Note: The world's population is on a steady rise. In the next 30 years, the world population is expected to rise by 2 billion people, from 7.7 billion at present to 9.7 billion in 2050 and could peak at nearly 11 billion around 2100.