The correct option is C 21 March
The International Day of Forests was established on the 21st day of March, by resolution of the United Nations General Assembly on November 28, 2012. Each year, various events are celebrated related to raising awareness of the importance of all types of forests, and trees outside forests, for the benefit of current and future generations. Countries are encouraged to undertake efforts to organize local, national, and international activities involving forests and trees, such as tree planting campaigns, on International Day of Forests. The Secretariat of the United Nations Forum on Forests, in collaboration with the Food and Agriculture Organization, facilitates the implementation of such events in collaboration with governments, the Collaborative Partnership on Forests, and international, regional and subregional organizations. International Day of Forests was observed for the first time on March 21, 2013.