Final answer:
A decryption key is a secret key or password that enables you to read encrypted information.
Step-by-step explanation:
The correct answer is 2) Decryption key. A decryption key is a secret key or password that enables you to read encrypted information. Encryption is the process of converting plaintext into ciphertext, while decryption is the reverse process of converting ciphertext back into plaintext. The decryption key is used in the decryption process to unlock the encrypted information.