<span>C. a scientific article</span>
Unicode is a universal computing standard to represent texts in most writing systems. It was invented to store most of the world's characters. It started during 1987. Joe Becker from Xerox was the one who made a proposal for Unicode.
Ella should view the presentation as a slideshow to see how it will look to her audience.
The purpose of the operating systems is to provide an interface between the user and hardware. It's mange all resources, for example; memory, processors, and disk space. It's also mange how to file and store data in a computer system.