Answer:
Track Changes
Step-by-step explanation:
This feature keeps track of all changes, modifications made in a document to be reviewed another time or by another person. This feature is used mostly for proofreading, editing and adding comments in a document file.
When the file/document is being reviewed later, the user can accept or reject changes made earlier. Accepting the change will make the change part of the document, while rejecting it will simply reject it.
New comment, and Accept Changes are part of Track Changes feature, while Show Markup is part of Formatting marks, required to view the formatting marks of a document.