What scrambles the contents of a file so you can't read it without having the right decryption key?

Answer: Option A

Encryption scrambles the contents of a file so you can't read it without having the right decryption key. Encryption is the process of encoding a message or information in such a way that only authorized parties can access it and those who are not authorized cannot. Encryption does not itself prevent interference, but denies the intelligible content to a would-be interceptor.