To help ensure that an HTML document renders well in many different web browsers, it is important to include which of the following at the top of the file.

A) an html tag

B) a doctype declaration

C) a body tag

D) a head tag

The detail answer of this question is given in explanation section.

The simple answer is option B

Explanation:

Let took at each option:

A) an html tag

An html tag is used to start and end html document. It does not have anything to do with rendering.

B) a doctype declaration

The document type declaration is necessary because it tell the browser which version of html should be rendered.

C)Body tag tell the browser. it is the visible area of website.

D) A hear tag is used to clear meta data about website.

I think it is:

Explanation:

a local network will allow everyone in the office to share the printer.

the answer to your question would be something called hertz. the unit of measurement called a hertz, which is one cycle per second, is used to measure clock speed. within one cycle, your computer processes, refreshes, or updates itself to the changes that it is going through. in the case of computer clock speed, one hertz equals one tick per second. the clock speed of computers is usually measured in megahertz (mhz) or gigahertz (ghz)