<prompt> Renal collar which surrounds the aoa has its two limbs split by:Left renal veinLeft renal aeryIsthmus of horseshoe kidneyAll of the above  <response>: Renal collar The main renal vein divides and sends one limb anterior and another limb posterior to aoa to reach the IVCQ. Formed on the left side and represent persistence of the embryonic state. 