**Core Concept**
The internal capsule is a deep structure of the brain, consisting of a mass of nerve fibers that are arranged in a specific pattern. The genu of the internal capsule is a part of this structure, connecting the posterior limb to the anterior limb and plays a crucial role in the transmission of motor and sensory signals.

**Why the Correct Answer is Right**
The genu of the internal capsule primarily carries the anterior thalamic radiation, which is a bundle of fibers that connect the thalamus to the frontal lobe. This radiation is involved in the transmission of motor and sensory information from the thalamus to the cortex. The genu also contains the sublenticular part of the internal capsule, which carries some of the corticobulbar and corticospinal fibers.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the anterior limb of the internal capsule primarily carries the anterior thalamic radiation, not the genu.
**Option B:** This option is incorrect because the posterior limb of the internal capsule carries the posterior thalamic radiation, not the genu.
**Option C:** This option is incorrect because the retrolenticular part of the internal capsule carries the optic radiation, not the genu.

**Clinical Pearl / High-Yield Fact**
The genu of the internal capsule is an important landmark in neurosurgery and neurology, and damage to this area can result in significant motor and sensory deficits. It's essential to remember that the genu is located deep within the brain and is surrounded by critical structures, making precise surgical or diagnostic techniques crucial.

**Correct Answer: C. Optic radiation is carried by the retrolenticular part of the internal capsule.