Which Event Dramatically Changed the Outcome of the Seven Years

Multiple Choice

Which event dramatically changed the outcome of the Seven Years' War?

A) George II's death in 1760, which left Hanover vulnerable to attack by Prussia and brought Great Britain into the war
B) The Turks' unexpected entry into the war on the side of Prussia, through which they hoped to regain territory lost to their joint enemy, Austria
C) The death of Empress Elizabeth of Russia, after which her successor immediately reversed her anti-Prussian policy, allowing Frederick the Great to escape a crushing defeat
D) The great Lisbon earthquake of 1755, which so devastated the French and Spanish economies that those countries were unable to fully pursue the war