Which of the following is an example of a delusion?

Believing that you are the president of the United States is an example of a delusion because it represents a strongly held belief that is clearly false and inconsistent with reality. Delusions are characterized by their persistence despite contrary evidence and are often associated with various mental health disorders, such as schizophrenia or delusional disorder. In this case, the belief in being a prominent figure like the president demonstrates a significant disconnect from reality.

While having an irrational fear of spiders reflects a specific phobia, it does not involve a false belief about oneself or the world in the way delusions do. Similarly, thinking that everyone is watching you can indicate paranoia or heightened self-consciousness, which might not qualify as a delusion unless the belief is distinctly unfounded and held firmly. Hearing voices that are not present is generally categorized as a hallucination rather than a delusion, as it involves perceiving stimuli that do not exist in the actual environment.