Correct Option: D

A section that is tangentially related to its surrounding content is defined by <aside> tag. A block of navigation links is provided by newly added element in HTML5 called <nav>. <hgroup> tag has been removed from HTML5 specification, but it can be seen in WHATWG version of HTML. The purpose of this element is how headings are displayed. It’s practice is limited to theory only. <figure> tag specifies its own self defined content which may contain diagrams, photos etc.