Multipurpose Internet Mail Extension (MIME) is a (1) document messaging standard in the Internet enviroment, with MIME, users can send (2) Email messages that include audio, video, graphices, and text to any other user of a TCP/IP network. Richtext information can also be (3) into messages. It defines the fonts, formats, and (4) features of a document so the document can be easily (5) on many different types of systems.

4（）

A．color

B．size

C．design

D．layout