**Core Concept**
6th cranial nerve palsy, also known as abducens nerve palsy, affects the lateral rectus muscle, leading to an inability to abduct the affected eye. This results in a specific type of strabismus characterized by esotropic deviation of the affected eye, with the affected eye turning inward.

**Why the Correct Answer is Right**
The loss of lateral rectus muscle function causes the affected eye to move inward, resulting in esotropia. This is because the medial rectus muscle, which is the primary muscle responsible for adduction, becomes overactive due to the unopposed action, causing the eye to turn inward. The affected eye is unable to abduct, and the patient often experiences double vision (diplopia) due to the misalignment of the eyes.

**Why Each Wrong Option is Incorrect**
* **Option A:** Esotropia is the correct answer, not exotropia, as the affected eye turns inward due to the unopposed action of the medial rectus muscle.
* **Option B:** Hypertropia is incorrect because 6th cranial nerve palsy primarily affects the vertical alignment of the eyes, causing esotropia, not hypertropia.
* **Option C:** Intorsion is incorrect because 6th cranial nerve palsy primarily affects the horizontal alignment of the eyes, causing esotropia, not intorsion.

**Clinical Pearl / High-Yield Fact**
It is essential to note that 6th cranial nerve palsy can be caused by various factors, including diabetes mellitus, hypertension, and head trauma. A thorough medical history and physical examination are crucial in diagnosing the underlying cause of the 6th cranial nerve palsy.

**Correct Answer: A. Esotropia**