Which one would be considered critical information

On early television stations, what typically filled the screen from around 11pm until 6am? test dummies test patterns tests testing colors

What is the primary difference between the header section of a document and the body? a. the body is displayed on the webpage and the header is not. b. the header is displayed on the webpage and the body is not. c. the tag for the body is self-closing, but the tags for the headers must be closed. d. the tag for the header is self closing, but the tag for the body must be closed.

Me if you do then you get 10 points and brainliest