I looked up the meanings of the two words and amenable means open and responsive to suggestion; easily persuaded or controlled. And docile ready to accept control or instruction; submissive. I really dont know what the answer is but i hope the defintions help
I would say 'A' Incredulous.
Hope i helped!
Something along the lines of,"if you do not do as i wish you will be eaten by the monster in the cave, something or someone that i control..."