Respuesta :
The answer is: factual.
Tone is the attitude or feeling of the author as regards the topic or subject of a piece of writing. The excerpt has a factual tone because it is concerned with the actual, genuine reality rather than perceptions or reactions towards it.
The tone is not emotional because it does not relate to anybody's emotions. Mysterious is not correct either since the events are not difficult to understand or explain. Finally, the tone is not critical for the reason that the text does not express disapproval or objection.