**Core Concept**
The abductors of the larynx are muscles responsible for the movement of the vocal cords apart, a crucial action in breathing. This movement is essential for the opening of the glottis, allowing for airflow during inhalation.

**Why the Correct Answer is Right**
The posterior cricoarytenoid muscles are the only abductors of the vocal cords. They achieve this by pulling the arytenoid cartilages medially, thereby rotating the vocal cords apart. This action is facilitated by the muscle's attachment to the posterior surface of the cricoid cartilage and its insertion into the arytenoid cartilage. The posterior cricoarytenoids play a vital role in maintaining airway patency during inspiration.

**Why Each Wrong Option is Incorrect**
**Option B:** The transverse arytenoids are not the primary abductors of the larynx; rather, they are involved in the approximation of the arytenoid cartilages, facilitating vocal cord closure during phonation.
**Option C:** The cricothyroid muscle is primarily responsible for tensing and lengthening the vocal cords, which is essential for increasing pitch during speech. It does not contribute to the abduction of the vocal cords.

**Clinical Pearl / High-Yield Fact**
In cases of bilateral posterior cricoarytenoid muscle paralysis, patients may experience significant respiratory distress due to the inability to abduct the vocal cords, leading to glottic stenosis and obstruction of the airway.

**✓ Correct Answer: A. Posterior cricoarytenoids**