Which tags should you use to wrap the H1, H2, and H3 elements?

You are developing a blog web page that is being optimized for accessibility. The page includes the following HTML.

The heading tags represent a blog post title, a blog post subtitle, and the author’s name.
You need to ensure that the three headings are treated as a unit but retain their individual
formatting.
Which tags should you use to wrap the H1, H2, and H3 elements?

A.
<group> </group>

B.
<header> </header>

C.
<hgroup> </hgroup>

D.
<headings> </headings>