This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
Nucleus gracilis and Nucleus cuneatus are the first synapses for 
Select and explain. 
A. Dorsal columns, B. Ventral spinothalamic tract, C. Dorsa lateral tract, D. Lateral spinothalamic tract
A: Dorsal columns
Answer: A: Dorsal columns 
Explanation: (A) Dorsal columns > Primary afferent neurons are located in dorsal root ganglion cells, and fibers (group II) ascend ipsilaterally and coalesce in the fasciculus gracilis or fasciculus cuneatus.> And these two fasciculi form the dorsal columns of the spinal cord and ascend the length of the spinal cord to nucleus gracilis and nucleus cuneatus of the medulla.> The Fasciculus gracilis consists of fibres from sacral and lumbar region and Fasciculus cuneatus receives its fibres from thoracic and cervical.