How does a handler know what exercise he must do in versatility obedience?

The correct answer highlights that the handler draws an envelope with exercises in it as the method for determining which specific exercises to perform in versatility obedience. This system introduces an element of surprise and variability into the trial, ensuring that handlers cannot overly rely on past experiences or predetermined routines. Each envelope typically contains specific instructions or exercises that the handler must then prepare their dog to perform, which aligns with the unpredictable nature of real-world situations that training in obedience seeks to simulate. This method encourages handlers to be adaptable and knowledgeable about a broad range of commands and exercises, enhancing their overall skill and their dog's responsiveness.

Other options may suggest less dynamic methods of exercise selection. For instance, a guidebook would provide static information that doesn't change from trial to trial, limiting adaptability. Consulting with a judge prior to the trial could imply pre-defined exercises, which might not promote the spontaneity needed for versatility obedience. Lastly, following a standard routine from previous trials does not account for the necessity of being flexible and ready to handle different exercises that may arise, which is crucial for success in these situations.