Final answer:
Colonel Mustard is the character who shows surprise upon learning someone is FBI in Scene 14.
Step-by-step explanation:
In Scene 14, the character that expresses surprise at the revelation that someone is FBI is c) Colonel Mustard. This scene is often filled with dramatic turns and character reactions that are pivotal to the development of the story. The surprise shown by Colonel Mustard adds to the suspense and unfolding mystery of the narrative in this scene.