ANS: D (ventral root) Ventral root: The spinal cord grows into ventral and dorsal sides. The Posterior median sulcus groove is called dorsal side and anterior median sulcus groove is called ventral side The ventral roots contain efferent fibers and dorsal root contains afferent fibers. The dorsal roots contain afferent fibers and the ventral roots contain efferent fibers. Solution ANS: D (ventral root) Ventral root: The spinal cord grows into ventral and dorsal sides. The Posterior median sulcus groove is called dorsal side and anterior median sulcus groove is called ventral side The ventral roots contain efferent fibers and dorsal root contains afferent fibers. The dorsal roots contain afferent fibers and the ventral roots contain efferent fibers..