<prompt> A 44- years old man presented with acute onset of low backache radiating to the right lower limb. Examination revealed SLRT 40 on the right side, weakness of extensor hallucis longus on the right side, sensory loss in the first web space of the right foot and brisk knee jerk. Which of the following is the most likely diagnosis -Prolapsed intervertebral disc L4-5Spondylolysis L51Lumbar canal stenosisSpondylolisthesis L4-5  <response>: Acute onset of low backache radiating to right lower limb, positive SLR test SLR 40 and weakenss of EHL suggest the PID at L45 level with compression of L5 root. 