Add a callout
Use the Callout tool to create a boxed text comment that points to a specific item.
Click Review & Comment
, and choose Comment & Markup Tools > Callout Tool.
Click where you want the end point to appear, and then move the pointer and click again to position the text box.
Type the desired text.
(Optional) Select the callout, and drag to reposition the pointer, the text box, or the entire callout.