In 2019, United Nations General Assembly adopted the resolution to hold an International Day of Clean Air for blue skies every year on ___________.

Correct option is C

The correct answer is (C) 7th September.

Explanation:
In 2019, the United Nations General Assembly adopted the resolution to observe the International Day of Clean Air for Blue Skies every year on 7th September. This day aims to raise awareness about the importance of clean air and to encourage actions for reducing air pollution.

Incorrect Options Explanation:

• 15th September: Not the correct date for the International Day of Clean Air for Blue Skies.
• 30th September: Not related to this specific observance.
• 1st October: Not the correct date for the International Day of Clean Air for Blue Skies.

Information Booster:

• International Day of Clean Air for Blue Skies:
  • Adopted by the United Nations General Assembly in 2019.
  • Celebrated annually on 7th September.
  • Focuses on actions to combat air pollution.