Correct Option: C

For grouping together set of one or more <h1> to <h6> element we use <hgroup> element. We can group together the primary heading and the subheading. E.g. <hgroup> <h2> Winter is coming! </h2> <h3> Its too cold </h3> </hgroup>. Grouping of related content together is done by <section> element. For grouping together related elements we use <div> element. An introductory content lies in <header>.