**Core Concept**
Stereognosis is the ability to identify an object through touch and manipulation, relying on the integration of sensory information from various parts of the body. This complex function is mediated by the posterior column-medial lemniscus pathway, which transmits sensations of touch, pressure, vibration, and proprioception.

**Why the Correct Answer is Right**
The fasciculus cuneatus is a part of the posterior column of the spinal cord that carries sensory information from the upper body, including the arms and hands. Damage to this pathway can result in the loss of stereognosis, as the brain is unable to integrate the necessary sensory information to accurately identify objects. The fasciculus cuneatus is responsible for transmitting sensations from the upper limbs to the brain, making it a critical component of the stereognostic pathway.

**Why Each Wrong Option is Incorrect**
**Option A:** The fasciculus gracilis is also a part of the posterior column, but it primarily carries sensory information from the lower body, including the legs and feet. Damage to this pathway would result in loss of proprioception and vibration sense in the lower limbs, but not stereognosis.
**Option C:** The anterior spinothalamic tract carries pain and temperature sensations from the body to the brain and is not involved in stereognosis.
**Option D:** The lateral spinothalamic tract also carries pain and temperature sensations, but from the opposite side of the body, and is not responsible for transmitting the necessary sensory information for stereognosis.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that damage to the posterior column of the spinal cord can result in a range of sensory deficits, including loss of proprioception, vibration sense, and stereognosis. The specific deficits will depend on the location and extent of the lesion.

**✓ Correct Answer: B. Fasciculus cuneatus**