<span>b. the assassination of archduke francis ferdinand.
</span>
Answer:
Disease, war, and possibly weakened government
Explanation:
"<span>The British hoped to tighten control over the empire" would be the best option, but the main reason beyond this was that they wanted to discourage trade with other nations, in order to increase profits. </span>
<span>C) the invasion of Poland
It happened in 1939, before all of the other events.
Hope this helps :)</span>