**Core Concept**
The internal capsule is a critical structure in the brain that serves as a conduit for ascending and descending motor and sensory pathways. It is divided into three main parts: the anterior limb, the genu, and the posterior limb. The posterior limb, specifically, is a complex region that contains the corticospinal and corticobulbar tracts.

**Why the Correct Answer is Right**
The recurrent artery of Heubner primarily supplies the anterior limb and the head of the caudate nucleus, which are not part of the posterior limb of the internal capsule. This artery is a branch of the anterior cerebral artery and plays a crucial role in supplying blood to the anterior limb of the internal capsule, as well as the anterior perforating substance. In contrast, the posterior limb of the internal capsule receives blood supply from other arteries, which are listed as options in this question.

**Why Each Wrong Option is Incorrect**
**Option A:** The middle cerebral artery (MCA) supplies a significant portion of the lateral surface of the brain, including the frontal, parietal, and temporal lobes. The MCA also supplies the posterior limb of the internal capsule, either directly or indirectly through its perforating branches.

**Option C:** The anterior choroidal artery typically supplies the posterior limb of the internal capsule, as well as the optic tract, the crus cerebri, and the choroid plexus of the lateral ventricle.

**Option D:** The posterior cerebral artery (PCA) supplies the occipital lobe and the posterior part of the temporal lobe, as well as the posterior limb of the internal capsule.

**Clinical Pearl / High-Yield Fact**
The posterior limb of the internal capsule is particularly vulnerable to damage from strokes, tumors, and infections, which can lead to significant motor and sensory deficits. It is essential to recognize the specific blood supply to this region to accurately diagnose and treat such conditions.

**✓ Correct Answer: B. Recurrent artery of Heubner**