Answer: A) Strangles/Creep.
Step-by-step explanation: The tone of a text or sentence is the author's or speaker's attitude towards the audience, the subject or even the characters of the text. There are many different kinds of tones, like: positive, negative, objective, sad, angry, etc. From the given options, the words that express the disturbing tone in the excerpt, are the corresponding to option A: Strangles and creep, which create the sensation of something mysterious.