**Core Concept**
The optic tract is a crucial part of the visual pathway that transmits visual information from the optic chiasm to the lateral geniculate nucleus of the thalamus. Lesions in the optic tract can lead to visual field defects, which are characteristic of the affected area.

**Why the Correct Answer is Right**
A lesion in the optic tract results in homonymous hemianopia, which is a visual field defect affecting the same half of the visual field in both eyes. This occurs because the optic tract carries fibers from the nasal half of each retina, which correspond to the temporal visual field. When these fibers are damaged, the corresponding visual field is lost in both eyes. The optic tract lesion spares the macula, which is the central part of the retina responsible for high-acuity vision, leading to a homonymous hemianopia without macular sparing.

**Why Each Wrong Option is Incorrect**
**Option A:** Binasal hemianopia is caused by a lesion in the optic chiasm, not the optic tract. This type of defect affects the nasal visual field in both eyes.
**Option B:** Bitemporal hemianopia is also caused by a lesion in the optic chiasm, typically due to a pituitary tumor pressing on the chiasm. This type of defect affects the temporal visual field in both eyes.
**Option C:** Homonymous superior quadrantonopia is a rare type of defect that affects the upper quadrant of the visual field in both eyes. It is typically caused by a lesion in the optic radiation or the lateral geniculate nucleus, not the optic tract.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that lesions in the optic tract typically cause homonymous hemianopia without macular sparing. This is because the optic tract carries fibers from the nasal half of each retina, which correspond to the temporal visual field. The macula, which is the central part of the retina responsible for high-acuity vision, is spared in optic tract lesions.

**✓ Correct Answer: D. Homonymous hemianopia**