A. October 10
B. Second Saturday of October
C. October 09
D. Second Friday of October
Explanation:
Every year, the World Migratory Bird Day (WMBD) is officially celebrated twice in a year since it started in 2006. Firstly it is held on Second Saturday of May and again on Second Saturday of October. In 2021, the WMBBD falls on May 08, 2021 and October 09, 2021.