## Core Concept
The question tests the understanding of psychiatric symptoms, specifically delusions. Delusions are fixed, false beliefs that are not amenable to change in light of conflicting evidence. They can be a feature of various psychiatric disorders, including schizophrenia.

## Why the Correct Answer is Right
The scenario describes a person who believes that others are implanting a machine on his head. This belief is a classic example of a **delusion of control**, specifically a **thought insertion or control delusion**, where the person believes that their thoughts are being controlled or influenced by external forces or agents. This type of delusion is characteristic of schizophrenia, particularly the subtype known as delusional disorder or schizophrenia with prominent delusions.

## Why Each Wrong Option is Incorrect
- **Option A:** Without the specific text of Option A, it's impossible to directly address why it's incorrect. However, if it doesn't describe a type of delusion or a psychiatric symptom related to the belief of external control over one's thoughts or body, it would be incorrect.
- **Option B:** Similarly, without the text, we can't directly address its incorrectness. If Option B suggests a different psychiatric symptom that doesn't align with the belief of others controlling one's thoughts or bodily functions, it would be incorrect.
- **Option C:** This option is not provided, but if it were to describe a different type of psychiatric symptom not related to delusions of control, it would be incorrect.

## Clinical Pearl / High-Yield Fact
A key point to remember is that delusions of control, including thought insertion or withdrawal, are **first-rank symptoms** of schizophrenia according to Schneider's criteria. These symptoms are highly suggestive of schizophrenia but are not exclusive to it. Recognizing these symptoms is crucial for diagnosing and managing schizophrenia.

## Correct Answer: D. Delusion of control.