**Core Concept**
The presence of contusion of neck muscles along with fracture of the hyoid bone in a postmortem examination suggests a case of strangulation, which is a form of mechanical asphyxia. This type of injury typically occurs due to external compression of the neck, causing obstruction of blood flow and ultimately leading to death.

**Why the Correct Answer is Right**
The correct answer is a case of manual strangulation, where the perpetrator applies direct pressure on the neck using their hands. This causes compression of the neck structures, including the trachea, esophagus, and blood vessels. The fracture of the hyoid bone is a classic indicator of strangulation, as it is a common site of injury in this type of trauma. The contusion of the neck muscles further supports this diagnosis, as it indicates blunt force trauma to the neck area.

**Why Each Wrong Option is Incorrect**
* **Option B:** This option is incorrect because a fracture of the hyoid bone is not typically associated with hanging, where the ligature is applied to the neck from above. Hanging often results in a fracture of the cervical spine or ligature marks on the neck.
* **Option C:** This option is incorrect because a fracture of the hyoid bone is not a common feature of smothering, which involves covering the nose and mouth to obstruct airflow. Smothering typically results in signs of respiratory compromise, such as petechial hemorrhages on the face and lungs.
* **Option D:** This option is incorrect because a fracture of the hyoid bone is not typically associated with drowning, which involves submersion in water. Drowning often results in signs of respiratory and cardiac compromise, such as pulmonary edema and cardiac arrhythmias.

**Clinical Pearl / High-Yield Fact**
The presence of a fractured hyoid bone in a postmortem examination should raise suspicion for strangulation, as it is a classic indicator of this type of trauma. It is essential for forensic pathologists to carefully examine the neck structures and look for other signs of trauma, such as contusions and ligature marks, to determine the cause of death.

**Correct Answer: A. Manual strangulation.**