WORLD HISTORY

Detailed explanation-1: -Austria-Hungary declares war on Serbia. Germany declares War on Russia. Germany declares war on France. Britain declares war on Germany.

Detailed explanation-2: -So, due to the assassination of Austrian Prince archduke and his wife Sophia on June 28, 1914, Austria-Hungary declared war on Serbia for the primary time. Thus, the correct answer is option ‘B’ i.e, Austria-Hungary.

Detailed explanation-3: -Austria-Hungary was one of the Central Powers in World War I, which began with an Austro-Hungarian war declaration on the Kingdom of Serbia on 28 July 1914. It was already effectively dissolved by the time the military authorities signed the armistice of Villa Giusti on 3 November 1918.

Detailed explanation-4: -On July 28, 1914, one month to the day after Archduke Franz Ferdinand of Austria and his wife were killed by a Serbian nationalist in Sarajevo, Austria-Hungary declares war on Serbia, effectively beginning the First World War.

Detailed explanation-5: -Telegram of Austria-Hungary‘s declaration of war on Serbia on 28th July 1914. Telegram of Austria-Hungary‘s declaration of war on Serbia on 28th July 1914 marked the beginning of the First World War – one of the world’s most tragic conflicts in the history of human race and initiated the era of unprecedented suffering.

Detailed explanation-6: -Following the declaration of war on Germany, Russian Emperor Nicolas II issued a manifesto announcing that in response to the Austro-Hungarian declaration of war against the Russian Empire, Russia would enter into war against Austria-Hungary. This occurred on on July 26, 1914.