14 February is observed as –

World Vegetarian Day
United Nations Day for South-South Cooperation
Valentine's Day
United Nations Day, recognized by the UN

The correct answer is C. Valentine’s Day.

World Vegetarian Day is observed on October 1.

United Nations Day for South-South Cooperation is observed on December 19.

United Nations Day is observed on October 24.

Valentine’s Day is a holiday celebrated on February 14 by lovers, romantic partners, and best friends, to express their love, affection, and appreciation for each other. It is a day for people to express their love for each other by giving cards, flowers, chocolates, and other gifts.