Final answer:
When Cindy saw the threatening stimulus, the sequence of activation of structures in her brain was prefrontal cortex, hypothalamus, amygdala.
Step-by-step explanation:
The sequence of activation of structures in Cindy's brain when she saw the threatening stimulus is d) Prefrontal cortex, hypothalamus, amygdala. The prefrontal cortex is responsible for higher-level cognitive processes, such as interpreting the threatening stimulus. The hypothalamus is involved in activating the sympathetic fight-or-flight response in response to the amygdala's input. The amygdala plays a key role in processing emotional information and triggering fear responses.