Which best explains why Germany sided with Austria-Hungary following the assassination of Archduke Ferdinand?
The countries shared a border.
The countries had an existing alliance.
The countries were blamed for his death.
The countries both wanted to build colonial empires.

The countries had an existing alliance.

Explanation:

Germany gave blank cheque assurance to whatever step Austria-Hungary takes against Serbia even if Russia intervenes, Germany was ready to offer its help. Historians have referred to as the carte blanche or “blank check” assurance which marked a decisive moment in the chain of events leading  to the outbreak of the First World War in Europe.

Arch Duke Ferdinand was the Emperor of Austrian Hungary who was assassinated by a Serbian Nationalist on his visit to Bosnia. This demise shook the emotions of Wilhelm Kaiser of Germany who had just visited Archduke Ferdinand just two weeks back and there were a cordial ties between Germany and Austria-Hungary.

Germany sided with Austria-Hungary following the assassination of Archduke Ferdinand-The countries had an existing alliance

Explanation:

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