Concept:World Environment Day is a global annual event designated by the United Nations to encourage awareness and action for environmental protection.
Explanation:This day is celebrated every year on 5th June, starting from 1974.
It aims to address issues like ozone depletion, toxic chemicals, desertification, and global warming.
Each year, a different country hosts the official celebration; for example, in 2019 China hosted it with the theme "Beat Air Pollution".
The theme for 2021 was "Ecosystem Restoration" with the slogan "Reimagine, Recreate, Restore".
Other significant environmental days include World Ozone Day (16th September) and World Population Day (11th July), but World Environment Day is fixed on 5th June.
Answer:Option C – 5th June