D. Government and law enforcement want access to encrypted messaging apps to help fight criminals and terrorists.
Explanation:
The explanation is simple: if a messaging application has encryption implemented into its functionality, then it means one of the purposes of that application is maintaining the privacy of the end user.
If a government and the law enforcement under that government want access to encrypted messaging applications with the intention of fighting criminals and terrorists -- which is an altruistic act to maintain security in the country -- this defeats the purpose of maintaining the end user's privacy if the developer(s) of the app were to hand over that data to a government and the law enforcement under them.
This is a famous example of security vs privacy, actually.
