Final answer:
The central theme of the excerpt 'The Trip of Le Horla' is the power of the human mind to create and manifest its own fears and anxieties.
Step-by-step explanation:
The central theme of the excerpt 'The Trip of Le Horla' is A) The power of the human mind to create and manifest its own fears and anxieties. The excerpt explores the inner workings of the human mind, showcasing how it can conjure up fears and anxieties that feel real and overwhelming. The protagonist's experiences on the trip highlight the psychological power of the mind to shape one's perception of reality.