The correct option is A January 10
The World Hindi Day (WHD) is observed every year on January 10 to mark the first anniversary of World Hindi Conference (WHC) which was held in 1975. The first WHC was inaugurated by then Prime Minister Indira Gandhi. Apart from India, the language is also spoken in Nepal, Guyana, Trinidad and Tobago, Suriname, Fiji, and Mauritius. Apart from this, the National Hindi Divas (NHD) is celebrated every year in India on September 14 to mark the day on which the Constituent Assembly adopted Hindi written in Devanagari script as the Official Language of the Union.