**Core Concept**
The hymen is a thin membrane that partially covers the external vaginal opening. Tears or lacerations of the hymen can be a sign of sexual assault or trauma. Documenting such injuries requires a thorough and accurate record to aid in forensic investigation and legal proceedings.

**Why the Correct Answer is Right**
A medical professional, often a forensic nurse examiner, uses a specific tool to document the location, size, and shape of the hymenal tear. This documentation helps to establish the extent of the injury and provides valuable evidence in cases of alleged sexual assault. The tool used is typically a ruler or a calibrated instrument to measure the size and shape of the tear.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as there is no specific tool used to document tear of hymen. While a ruler or a calibrated instrument may be used to measure the size of the tear, it is not the primary tool for documentation.
**Option B:** This option is incorrect as there is no specific tool used to document tear of hymen. While a camera or photographs may be used to document the injury, it is not the primary tool for documentation.
**Option C:** This option is incorrect as there is no specific tool used to document tear of hymen. While a medical chart or documentation may be used to record the injury, it is not the primary tool for documenting the tear itself.

**Clinical Pearl / High-Yield Fact**
When documenting tears of the hymen, it is essential to use a calibrated instrument to measure the size and shape of the injury. This detail can be crucial in forensic investigations and may aid in establishing the extent of the trauma.

**Correct Answer: A. Ruler**