Okay, let's tackle this question. The question is about the palsy of the right genioglossus muscle. First, I need to recall what the genioglossus does. The genioglossus is a muscle of the tongue, innervated by the hypoglossal nerve (CN XII). Its main function is to protrude the tongue. If there's a palsy, the muscle would be paralyzed.

Now, if the right genioglossus is paralyzed, the tongue would deviate towards the affected side when the person tries to stick out their tongue. This is because the unaffected left genioglossus would still be functioning and pulling the tongue to the left, causing the right side to droop. So the correct answer should be deviation of the tongue to the right.

Looking at the options, the correct answer is the one stating deviation to the right. The other options might include things like deviation to the left, paralysis of other muscles, or unrelated symptoms. For example, if someone thought it was the hypoglossal nerve on the left, they might pick the wrong side. Also, confusion with other cranial nerves like facial nerve might lead to incorrect options.

The clinical pearl here is remembering that the genioglossus is innervated by CN XII and that unilateral palsy causes deviation towards the affected side. This is a classic exam point for neuroanatomy.

**Core Concept** The genioglossus muscle, innervated by the hypoglossal nerve (CN XII), is responsible for protruding the tongue. Unilateral paralysis causes the tongue to deviate toward the affected side due to unopposed action of the contralateral muscle.

**Why the Correct Answer is Right** A right genioglossus palsy impairs the ability of the right muscle to protrude the tongue. When the patient attempts to stick out their tongue, the intact left genioglossus pulls the tongue leftward, resulting in deviation **toward the right** (the affected side). This is a classic sign of hypoglossal nerve dysfunction.

**Why Each Wrong Option is Incorrect**
**Option A:** Deviation to the left is incorrect because the unaffected left genioglossus would dominate, pulling the tongue contralaterally.
**Option B:** Inability to protrude the tongue bilaterally is incorrect, as only the right muscle is affected.
**Option C:** Paralysis of the geniohyoid is unrelated to CN XII and does not cause tongue deviation.
**Option D:** Facial nerve (CN VII) palsy affects facial muscles, not tongue movement.

**Clinical Pearl / High-Yield Fact** Remember **"tongue deviates to the paralyzed side"** in hypoglossal nerve palsy. This distinguishes it from other cranial nerve palsies (e.g., facial nerve palsy affects facial symmetry, not tongue movement).

**Correct Answer: D. Deviation of the tongue to the right**

✓ Correct Answer: A. Detion of tongue to right