**Core Concept**
Venterolateral cordotomy is a surgical procedure aimed at relieving pain by interrupting the spinothalamic tract, a major pathway for pain and temperature sensation in the spinal cord. This procedure targets the lateral spinothalamic tract, which carries pain and temperature information from the contralateral side of the body.

**Why the Correct Answer is Right**
The spinothalamic tract originates from the dorsal horn of the spinal cord and ascends through the lateral funiculus. The venterolateral cordotomy involves making a lesion in the lateral part of the spinal cord to cut the spinothalamic tract, thereby interrupting pain signals from the right lower limb. This results in ipsilateral loss of pain and temperature sensation in the right lower limb, while other sensory modalities like touch and proprioception remain intact. The procedure is more effective for pain relief when performed on the lower limb due to the relatively straight course of the spinothalamic tract in this region.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because venterolateral cordotomy is not performed to relieve pain in the upper limb, as the spinothalamic tract has a more complex course in this region, making the procedure less effective.

**Option B:** This option is incorrect because venterolateral cordotomy is not a procedure for treating pain caused by damage to the peripheral nerves; rather, it targets the central nervous system.

**Option C:** This option is incorrect because venterolateral cordotomy does not involve cutting the motor tracts, which are responsible for controlling voluntary movements.

**Option D:** This option is incorrect because venterolateral cordotomy is not performed bilaterally; a unilateral lesion is sufficient to relieve pain from the contralateral side of the body.

**Clinical Pearl / High-Yield Fact**
A key consideration in venterolateral cordotomy is the identification of the correct dermatome and myotome levels for the procedure. This involves careful preoperative mapping and intraoperative localization to avoid damaging motor tracts and achieving optimal pain relief.

**Correct Answer: D. Venterolateral cordotomy is performed unilaterally to relieve pain from the contralateral side of the body.**