HELP PLEASE I WILL MARK BRAINLIEST Does anyone know unblocked music players please its urgent

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.

Which of the following terms refers to a collection of different types of software that share the goal of infiltrating a computer and making it do something? a- malware b- virus c- spyware d- trojan horse

Cylinder heads with four valves flow more air than those with two valves because they