Final answer:
The correct answer is option A. Isolate the incident and deny entry.
Step-by-step explanation:
When dealing with terrorist and criminal incidents, there are specific protocols that must be diligently followed to ensure the safety of all individuals involved, as well as the integrity of the ongoing investigation. One of the fundamental guidelines is to isolate the incident and deny entry. This means establishing a secure perimeter around the incident site to prevent unauthorized individuals from entering, which could potentially compromise the scene or lead to further danger. This directive aligns with procedures geared towards preserving evidence and maintaining control over the situation.
Arresting suspects, taking photographs, or allowing people and animals to leave hastily are actions that might be considered later, but they are not immediate universal guidelines.
Each of these actions would be assessed and conducted based on specific circumstances and in accordance with legal and procedural considerations.