Final Answer:
The tool for adding a page number as a Footer is available in the Insert menu. (Option a is the correct answer.)
Step-by-step explanation:
Adding page numbers, headers, and footers to a document belongs to the category of inserting elements into the document. Therefore, the tool for this task would be located in the Insert menu.
Here's a breakdown of the other options and why they're not the correct answer:
View: This menu controls how the document is displayed, such as zoom level, layout mode, and navigation options. It doesn't offer tools for inserting content like page numbers.
Edit: This menu contains tools for manipulating text and formatting paragraphs, but it doesn't include features specifically for adding page numbers.
Format: This menu provides options for adjusting the appearance of text and paragraphs, such as font styles, margins, and alignment. While it may offer some options for formatting page numbers after they've been inserted, it's not the primary location for adding them.
Therefore, when you want to add a page number as a Footer in most word processing applications, you'll find the relevant tools within the Insert menu.
Option a is the correct answer.)