Which of the following best describes an illusion?

A. False belief that someone is following. This describes a persecutory delusion, a type of false, fixed belief where a person is convinced they are being watched, followed, or harmed despite no evidence. Delusions are thought disturbances, whereas illusions involve misinterpretations of sensory stimuli. B. Misinterpretation of real experience. An illusion occurs when a person misperceives an actual external stimulus. For example, seeing a coat hanging in a dark room and mistaking it for a person. Unlike hallucinations, illusions are based on real sensory input that is distorted or misinterpreted. C. Feeling things that are not there. This describes a tactile hallucination, where a person experiences false sensory perceptions of touch, such as bugs crawling on the skin. Tactile hallucinations are commonly seen in substance withdrawal (e.g., alcohol withdrawal, cocaine intoxication) and psychotic disorders. D. Hearing voices that are not there. This describes an auditory hallucination, the most common type of hallucination in schizophrenia and other psychotic disorders. Unlike illusions, hallucinations occur without any external stimulus and are perceived as real by the affected individual.