​The abbreviation S/MIME implies _________.​

Correct option is D

The correct expansion of S/MIME is Secure / Multipurpose Internet Mail Extensions. S/MIME is a widely used protocol for sending digitally signed and encrypted messages in MIME (Multipurpose Internet Mail Extensions) format. It ensures the confidentiality, integrity and authentication of email communication. Developed by RSA Data Security, S/MIME extends the standard MIME format by adding security features for secure email messaging, especially in enterprise environments.
Information Booster:
1. S/MIME provides:
a. Encryption to ensure message privacy.
b. Digital signatures to verify sender authenticity and ensure data integrity.
c. Certificate-based security using X.509 certificates.
2. Commonly supported in email clients like Microsoft Outlook, Apple Mail and Mozilla Thunderbird.
3. It is based on the Public Key Cryptography Standards (PKCS).