Which of the following guidelines about use of all capital letters in the email messages most important

The correct answer to this question would be to: Avoid the use of all capital letters because this is not grammatically correct. While using all capital letters may be good for getting someone's attention, e-mail is a formal communication method and proper grammatical rules should be followed which involve not using all capital letters for a word unless it is an acronym for something.

answer is:

a). backstage view

explanation:

backstage view is the area where files and data about them is managed— creating, saving, printing, sending to others, inspecting for hidden metadata or personal information, and setting options. so in this way we can add many things to our document swiftly.

i hope you get the idea.