**Core Concept**
Exhumation is the process of digging up a corpse from a burial site, typically for the purpose of conducting a post-mortem examination or collecting evidence in a criminal investigation. In the context of forensic medicine, exhumation is a sensitive procedure that requires careful consideration and authorization from the appropriate authorities.

**Why the Correct Answer is Right**
The district magistrate is the competent authority to order exhumation under Section 174 of the Code of Criminal Procedure (CrPC), 1973. This section empowers the district magistrate to order exhumation in cases where a corpse is suspected to be the result of a homicide or other suspicious circumstances. The district magistrate's order is necessary to ensure that the exhumation process is carried out in a lawful and dignified manner. The district magistrate's authority is derived from their position as the representative of the state, and their order is typically required to obtain a court warrant for exhumation.

**Why Each Wrong Option is Incorrect**
**Option A:** A doctor, while a medical expert, does not have the legal authority to order exhumation. While a doctor may be involved in the post-mortem examination process, they do not have the power to authorize the exhumation of a corpse.

**Option B:** A civil surgeon may be involved in the examination of a corpse, but they do not have the legal authority to order exhumation. The civil surgeon's role is typically limited to conducting the post-mortem examination and reporting their findings to the appropriate authorities.

**Option D:** A police commissioner may be involved in the investigation of a crime, but they do not have the legal authority to order exhumation. While the police commissioner may request exhumation as part of an investigation, they must obtain the necessary authorization from the district magistrate or other competent authority.

**Clinical Pearl / High-Yield Fact**
It is essential to note that exhumation should only be ordered in cases where it is strictly necessary, and the process should be carried out with dignity and respect for the deceased and their family. The district magistrate's order for exhumation should be obtained in a timely manner to avoid any unnecessary delay in the investigation or post-mortem examination process.

**✓ Correct Answer: C. District magistrate. The district magistrate is the competent authority to order exhumation under Section 174 of the Code of Criminal Procedure (CrPC), 1973.**