According to the Homeland Security Mission Areas, activating resources and coordinating responses in a hospital disaster exercise should stimulate thinking in which area

The correct answer is - Protection

Explanation:

There are five preparedness mission areas that are prevention, protection, mitigation, response, and recovery. In prevention, actions are taken to prevent an incident to occur that can harm life and property. Protection is the capability of securing life and homelands from violence created naturally or artificially.

So activating resources and coordinating responses in a hospital disaster exercise should focus on stimulating thinking in the protection area to avoid any causalities and damage to the patients. Therefore the correct answer is protection.