The correct completion of the sentence is:

You can never get away with stealing the presidential jet. You will be caught.

Explanation:
- "Get away with" is a common expression meaning to successfully avoid punishment or negative consequences for something, often something illegal or wrong.
- "Scot-free" is another term that means without suffering any punishment or harm, but the more common and suitable phrase in this context is "get away with" and not "get scot-free"
 
Therefore, the correct option is B. Away.