What communications technique can a hacker use to identity the product that is running on an open port facing the Internet?

To show a "hidden" row one (1 ) or a "hidden" column A

A) use only a Ribbon command with arrows . B) scroll to the left. C) type A1 in the name box and then press "Enter" D) scroll to the right.

In an XHTML page that contains no attribute, text will display at:

A) the default font size of the viewer's computer. B) a default size of 10 pts. C) a default size of 14 pts. D) the default size and width of the browser window.