Important National and International Days

Dr. B.R. Ambedkar's birthday (April 14, 1891) is celebrated as Ambedkar Jayanti across India. This is a fixed Gregorian date as it commemorates a specific historical birth date. April 14 is objectively correct and is a public holiday in several Indian states.

Gandhi Jayanti commemorates the birth of Mahatma Gandhi on October 2, 1869. Like Ambedkar Jayanti, this is a fixed Gregorian date as it marks a specific historical birth date. October 2 is correct and is a national holiday in India. International Day of Non-Violence is also observed on this date by the UN.

The first Earth Day was celebrated in San Francisco, CA on April 22, 1970. While events took place nationwide, San Francisco was one of the primary locations with extensive activities and celebrations.

This appears to be a Bangalore-specific trivia claim. Without authoritative verification of Bus Day being on the 4th of every month, this should be treated as local trivia that may or may not be accurate.

Amitabh Bachchan's birthday is October 11, 1942. Option B correctly states 11th October as his birth date.

National Maritime Day is celebrated in India on April 5 every year to commemorate the first Indian ship that sailed to Mumbai on April 5, 1919. The week surrounding this date is observed as National Maritime Week.

The October Revolution is celebrated in November because Russia used the Julian calendar at the time. The revolution began on October 25th (Old Style) but was November 7th (Gregorian/New Style).

World No Tobacco Day is celebrated on May 31 every year. This was established by the WHO in 1987 to draw attention to the tobacco epidemic and preventable deaths it causes. April 31 is not a valid date.

Earth Day is celebrated on April 22 every year. It was first established in 1970 to promote environmental awareness and protection. The date marks the spring equinox in the Northern Hemisphere.

World Health Day is celebrated on April 7 every year. It marks the founding of the World Health Organization (WHO) in 1948. Each year focuses on a specific health theme.

International Women's Day is celebrated on March 8 every year. It commemorates the movement for women's rights and equality. The day was first observed in 1911 and is now recognized globally.

NPC Day (National Pollution Control Day) is observed on December 2 every year in India. It commemorates those who lost their lives in the Bhopal Gas Tragedy in 1984 and emphasizes pollution prevention.