What information is crucial to note in a subject identification form before surveillance?

The correct response focuses on the importance of knowing the frequent travel destinations of a subject before conducting surveillance. This information is vital as it helps the investigator anticipate the subject's movements and locations, making it easier to plan the surveillance effectively. Understanding where a subject is likely to be at different times can greatly enhance the chances of gathering relevant information and making the investigation successful.

On the other hand, knowing personal opinions about the investigator, the number of friends a subject has, or their favorite food does not provide actionable intelligence relevant to surveillance planning. While they may contribute to a broader profile of the subject, they do not directly aid in the practical aspects of monitoring the subject's activities or patterns. Thus, recognizing frequent travel destinations stands out as the most useful piece of information in preparing for surveillance operations.