The correct answer is: B. double quotes
CSS is a stylesheet language used to describe the presentation of a document written in a markup language like HTML. CSS is designed to enable the separation of presentation and content, allowing web developers to create web pages that are both semantically correct and easy to style.
CSS uses a number of different types of strings, including:
- Identifiers are used to name elements, attributes, and classes. Identifiers must start with a letter or underscore, and can contain any combination of letters, numbers, and underscores.
- Strings are used to represent text. Strings can be enclosed in single quotes (‘) or double quotes (“).
- Comments are used to provide information about the code. Comments are ignored by the browser.
- Keywords are reserved words that have special meaning in CSS. Keywords cannot be used as identifiers.
The question asks which of the following strings are defined by CSS. The answer is double quotes, because double quotes are used to enclose strings in CSS. Single quotes can also be used to enclose strings, but double quotes are more common.
The other options are incorrect because they are not strings that are defined by CSS.