The best option from the list would be "<span>The guillotine was an effective instrument for instilling fear and conflict," since this is an opinion that needs to be supported with historical evidence. The other options are simply facts (or non-facts). </span>
Explanation:
Como toda guerra, la Segunda Guerra Mundial se debió a razones variadas y complejas, que pueden resumirse en:
Los términos del tratado de Versalles. ...
El surgimiento del fascismo. ...
Las tensiones chino-japonesas. ...
La invasión alemana de Polonia.
(y varias razones más)
Over 20 million people were injured in World War 1. Over 8 million died and 5 million were held prisoners.