Can someone give me advice on this no answer because what ever I put down will be right

The Archduke Franz Ferdinand of Austria was assassinated on this tragic day. The Archduke and his wife, Sophie, the Duchess of Hohenberg , were shot dead in Sarajevo . This ghastly act was undertaken by Gavrilo Princip , who was merely 19 years old at that time.  Happend on June 28,1914

Great Britain entered World War I on 4 August 1914 when the king declared war after the expiration of an ultimatum to Germany. the official explanation focused on protecting Belgian neutrality. The main reason, however, was to prevent a French defeat that would have left Germany in control of Western Europe .

Explanation:

i think the answer is b.

he sent troops to protect the students as they entered the school.