A. It is I. Should be your answer
Everyone (has) done his or her homework because 'everyone' means plural so there is plural already so don't need to put 'have'.
The answer is the second one,
;)
Sandford, legal case<span> in which the U.S. Supreme </span>Court<span> on March 6, 1857,</span>ruled<span> (7–2) that a slave (</span>Dred Scott<span>) who had resided in a free state and territory (where slavery was prohibited) was not thereby entitled to his freedom; that African Americans were not and could never be citizens of the United States</span>
