What is the spark that ignited the powder keg in the balkans and directly led to world war i? a. the assassination of kaiser wilhelm ii in vienna. b. the assassination of archduke franz ferdinand in sarajevo. c. the invasion of serbia by austro-hungarian troops. d. the announcement of an alliance between russia and serbia

B. the assassination of Archduke Franz Ferdinand in Sarajevo.

Explanation:

The Sarajevo attack is the term with which the murder is known, on June 28, 1914, of the crown heir of the Austro-Hungarian Empire, Archduke Francisco Fernando of Austria, and his wife, Duchess Sofia Chotek, in Sarajevo , capital of the imperial province of Bosnia and Herzegovina. The attack was perpetrated by Gavrilo Princip, a member of the Young Bosnia group, a movement whose objective was the emancipation of Bosnia from Austria-Hungary, which was supported by intelligence and military circles from the Kingdom of Serbia. This event was the trigger of the First World War.

the lachish letters were written by hoshaiah, a military officer stationed possibly in mareshah,   and sent to yaush, possibly the commanding officer at lachish.

the series of letters were written in carbon ink in ancient hebrew on clay ostraca, shortly before lachish fell to the babylonian army of king nebuchadnezzar in 588/6 bc during the reign of zedekiah, king of judah.