Answer:
option c.Once the dog can keep his nose attached to your baited hand as you change between the back-up exercise and the walking Heel.
Explanation:
heel cue is used for the dog to instantly take/assume a focused position at the owner's left side and remain there whether the owner is walking, standing still or running and also the dogs front legs should be even with the owner's legs at all times and it is as at when you want or need the dog's undivided attention and it can be also be used to redirect a dog's attention on walks or whenever she encounters distractions.