**Core Concept**
Hysteroscopy is a minimally invasive procedure that allows for the visualization of the uterine cavity using a hysteroscope, a thin, flexible or rigid telescope. The procedure is used for diagnostic and therapeutic purposes, including the evaluation of abnormal uterine bleeding, removal of polyps or fibroids, and assessment of infertility.

**Why the Correct Answer is Right**
The correct answer is likely related to the distension media used to fill the uterine cavity during hysteroscopy. Distension media are essential to create a clear visual field and to prevent the hysteroscope from touching the uterine walls. Carbon dioxide (CO2) and normal saline are commonly used distension media. CO2 is a popular choice due to its rapid absorption and minimal risk of fluid overload, whereas normal saline is often used when a more thorough evaluation of the uterine cavity is required.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a correct answer because it is not a commonly used distension media for hysteroscopy.
**Option B:** This option is not a correct answer because it is not a suitable medium for hysteroscopy due to its high viscosity and potential for causing uterine cramping.
**Option C:** This option is not a correct answer because it is not a commonly used distension media for hysteroscopy, and it may cause fluid overload.

**Clinical Pearl / High-Yield Fact**
It is essential to choose the correct distension media for hysteroscopy based on the individual patient's needs and medical history. For example, patients with a history of fluid overload or respiratory issues may require a different distension media.

**Correct Answer: B. Normal Saline.**