Final answer:
The Multipurpose Internet Mail Extensions (MIME) protocol specifies how email messages should be formatted so they can be exchanged between different email systems.
Step-by-step explanation:
The correct answer is b. MIME. The Multipurpose Internet Mail Extensions (MIME) protocol specifies how email messages should be formatted so they can be exchanged between different email systems. The Multipurpose Internet Mail Extensions (MIME) protocol specifies how email messages should be formatted so they can be exchanged between different email systems.
MIME allows for the transmission of multimedia attachments, such as images, audio, and video, along with the text of the email message. It defines the structure and encoding of these attachments to ensure compatibility across different email clients and servers.