What's a user agent?

A way to detect device properties and evaluate logical expressions in CSS.

A program that employs Web content in some way.

A way to identify the elements within an HTML document you want to style.

A way to style multiple pages with one style sheet.

Which symbol indicates an ID selector?

The pound sign or hash mark (#).

The asterisk (*).

The colon (:).

The period (.).

Which HTML element can you use to hold JavaScript code?