**Core Concept**
Supraglottic laryngeal carcinoma is a type of cancer that arises in the supraglottic region of the larynx, which includes the epiglottis, aryepiglottic folds, and the arytenoid cartilages. This region is located above the vocal cords and is a common site for laryngeal cancer, particularly in smokers and individuals with a history of alcohol consumption.

**Why the Correct Answer is Right**
The correct answer, **A. It is the most common site for carcinoma larynx**, is incorrect because the most common site for carcinoma of the larynx is actually the glottis, which includes the vocal cords. The glottis is a more common site for laryngeal cancer due to its higher exposure to carcinogens such as tobacco smoke and alcohol.

**Why Each Wrong Option is Incorrect**
**Option B:** Involvement of upper & middle jugular lymph nodes is seen. This is true, as supraglottic laryngeal carcinoma often spreads to the upper and middle jugular lymph nodes due to its location in the supraglottic region.

**Option C:** Point on swelling is the most common symptom. This is also true, as the initial presentation of supraglottic laryngeal carcinoma often includes a painless swelling or mass in the neck.

**Option D:** Stage T1 is treated by external beam radiation therapy. This is true, as stage T1 supraglottic laryngeal carcinoma is often treated with definitive radiation therapy, which includes external beam radiation therapy.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the most common site for carcinoma of the larynx is the glottis, not the supraglottic region. This distinction is crucial for accurate diagnosis and treatment planning.

**Correct Answer Line**
✓ Correct Answer: A. It is the most common site for carcinoma larynx