<prompt> All the following are contents of sub-occipital triangle, except -Vertebral arteryDorsal ramus of C1 nerveSuboccipital plexus of veinOccipital artery  <response>: Contents of suboccipital triangle are vertebral artery 3rd part, suboccipital nerve dorsal ramus of C1 and suboccipital venous plexus. Occipital artery lies in occipital triangle. 