**Core Concept**
The question revolves around the legal and investigative aspects of a dowry death, which is a specific type of domestic violence. In such cases, the investigation is critical for determining the cause of death and identifying those responsible. The **dowry death** is a serious issue in some countries, often linked to **domestic violence** and **gender-based violence**.

**Why the Correct Answer is Right**
Given the context of a dowry death, the investigation must be thorough and impartial. In many jurisdictions, such investigations are conducted by a **magistrate-level officer** or a **specialized team** to ensure that the evidence is properly collected and that the rights of all parties are respected. This approach helps in uncovering the truth behind the death and in bringing the perpetrators to justice.

**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because, while police officers are involved in the initial stages of investigation, dowry death cases often require a more specialized and higher-level investigation.
**Option B:** Similarly, this option is incorrect as it does not specify the level of investigation required for dowry deaths.
**Option D:** This choice is also incorrect as it does not align with the standard procedures for investigating dowry deaths.

**Clinical Pearl / High-Yield Fact**
In cases of suspected dowry death, it's crucial to remember that the investigation must be meticulous, considering both the medical aspects of the death and the legal implications. The role of **Section 498A of the Indian Penal Code** and the **Dowry Prohibition Act** is significant in such investigations.

**Correct Answer:** D. District Magistrate or Sub-Divisional Magistrate.