Multi-choice problem: Continue writing the next sentence in this paragraph:

How to teach your dog to bolt from a standing start
Make sure your dog is capable of this trick.
Bolting from a standing start requires that your dog is healthy and active so that he can run at a fast pace. Old or sick dogs may not be able to master this trick.

pick from the following.
A). Have a trainer help you teach your dog this trick. Most training programs require that you have a trainer stand your dog down in the sitting room..
B). It also helps if your dog has an energetic personality. Dogs who love to play chase or catch are often good candidates for this trick..
C). Opt for a younger dog if possible to increase the chances of him learning this trick. Older dogs tend to have more skills in certain areas, like jumping..
D). You do not want to find a dog who cannot do this trick at home. It's best to get an older dog or dog who is " certified " by a veterinarian..
B).