What device is used to select an encryption key from the radio's memory?

The Simple Key Loader (SKL) is the appropriate device utilized for selecting an encryption key from a radio's memory. The SKL allows users to load and manage encryption keys securely, ensuring that communication remains confidential and secure. This device operates by connecting to various types of radios and facilitates the transfer of encryption keys, allowing operators to quickly select the appropriate key required for secure communications.

In contrast to tools like the keypad, which serves primarily as a user input mechanism rather than a dedicated key management tool, the SKL is specifically designed with the security and logistics of key distribution in mind. The encryption module refers to the internal component responsible for executing the encryption algorithms but does not provide manual key selection or management capabilities. The Secure Access Device functions to secure access to sensitive information but is not specifically employed in the selection of encryption keys from the radio's memory. Thus, the SKL stands out as the dedicated and correct choice for this function.