Which Is the Correct Stance for Introducing a Balling Gun

Which is the correct stance for introducing a balling gun, dose syringe, or Frick's speculum in a cow?

A) Stand caudal to the animal's shoulder, facing away from the animal.
B) Stand cranial to the animal's shoulder, facing the same direction as the animal.
C) Stand facing the animal at eye level, with your nondominant hand on the animal's shoulder.
D) Stand anterior to the animal at a 45-degree angle from the animal's face and wrap the nondominant arm around the animal's shoulder.