Fact 1: Afirecracker converts chemical energy into sound.

Fact 2: Most any other sounds can be frightening or startling.

Given the two facts above, answer the question "What can be startling?" with the following options: 
- firecrackers
 - an image
 - Saltine crackers
 - Wheat crackers
 - an object
 - sea urchins
 - sameness
 - hypothyroidism


 

 firecrackers        