When was the International Day for Elder Persons 2021 celebrated?

Correct option is A

The correct answer is (a) 1 October.
 The International Day for Elder Persons is celebrated annually on 1 October.
 This day was designated by the United Nations General Assembly to recognize the contributions of older persons and to examine issues that affect their lives.
 The theme for the International Day for Elder Persons 2021 was "Digital Equity for All Ages," highlighting the importance of digital inclusion of older persons.