Only one of the tags below has all of the tags in the right order for proper testing. Which one is it?
a. <p>Hello <strong>there >em>world>/em>/p>/strings>
b. <p>Hello <strong> there <em>world</em>/strong></p>
c. <p>Hello <strong>there <em>world</p></strong></em>
d. <p>Hello <strong>there <em>world></strong></p</em>
<p>Hello <strong> there <em>world</em>/strong></p>