Which of the following is the preferred standard for responsive web design?

• A. Use Flash to control the appearance of the site and capture browser information.
• B. Use JavaScript to set all CSS style and control interactivity.
• C. Use CSS to organize the information and HTML to control the appearance of the site.
• D. Use HTML to format the web site and CSS to control the appearance of the site.

Answer: (D)

Responsive web design relies on keeping content separate from how it looks. HTML provides the structure and meaning of the content, while CSS controls the presentation, including layout, typography, and how things adapt at different screen sizes through features like media queries and flexible units. This separation makes sites easier to maintain, accessible, and capable of adjusting to phones, tablets, and desktops without changing the HTML.

Choosing to format the site with HTML and style it with CSS aligns with that approach. It lets the content remain semantic and the appearance adapt with CSS rules, which is essential for responsive behavior.

Flash is outdated and not suitable for responsive design. Using JavaScript to set all CSS styles or to control interactivity undermines the separation of concerns and can hurt performance and accessibility. Reversing the roles—having CSS organize information and HTML control appearance—misunderstands which layer handles structure versus presentation.