What feature is available to add a suggestion in the margin of someone else's document?

The correct answer to this question is given below in the explanation section.

Explanation:

The correct question is:

what feature is available to add a suggestion in the margin of someone else's document. The given features in this question are:

The correct answer to this question is the Comments.

Because you can add comments in someone else's document and only Comments features in word document allow you add comments on the someone else's document.

While the other options are not correct because:

The Annotation works with grammar or writing, Highlight feature allows you to mark important information or text in your document. while Bookmark allows you to save your space in a document.

the save and close button

that without the operating systems you would have to control and synchronize computer hardware.