a) <q>
b) <blockquote>
c) <em>
d) <abbr>

Answer: a
Explanation: <em> element indicates emphasis, browser will show the contents of <em> element in italic. A section which is quoted from another source is specified by <blockquote>. The <abbr> defines abbreviation. We used <q> element for shorter quote. Browser put quote around <q> element.
Example: <p>This is a <q>brown dog</q>.</p>
Output: This is a “brown dog”.